Take Official EV Range Numbers With A Grain Of Salt


Range numbers are a good way to compare EVs. But are they real?

When electric cars were introduced eight years ago, the U.S. Environmental Protection Agency introduced a new term: miles per gallon equivalent. Applying a term related to gallons of liquid fuel for EV efficiency was immediately criticized for being confusing if not misleading. Today, the EPA also shows the number of kilowatt-hours required to travel 100 miles (easily translated to miles per kWh), as well as the total estimated range of an EV. Unfortunately, these numbers are also difficult to relate to real-world, everyday driving.

The issue emerged again this week when the EPA officially rated the Jaguar I-Pace with an efficiency of 44 kWh per 100 miles and a total driving range of 234 miles. That’s a far cry from previous tests, such as the 292 miles of range indicated by the generous Worldwide Harmonized Light Vehicles Test Procedure (WLTP) and the 291 miles achieved by Top Gear, which was aiming for a long-range number with gentle driving manners.

The I-Pace’s numbers are commonly compared to the larger and heavier Tesla Model X, which is rated at 39 kWh per 100 miles – and a driving range of 295 miles. The differences between the two ratings seem to confirm what Tesla’s Elon Musk said in the company’s most recent earnings call: “We have the best in terms of miles or kilometers per kilowatt hour, and we also have the lowest cost per kilowatt-hour. This makes it very difficult for other companies to compete with Tesla because we’re the most efficient car and have the lowest-cost batteries.” Musk was mostly talking about the company’s latest technology found in the ultra-efficient Model 3 rather than the Model X, which is an older system.

InsideEVs reached out to Michael Duoba, chief engineer of the Advanced Powertrain Research Facility at Argonne National Lab, for his insights. “I ran a simple model of the I-Pace’s driving losses and it seems the 2017 Model X 90D has about 7 percent fewer driving losses, and about 10 percent higher powertrain efficiencies than the I-Pace,” said Duoba. “Efficiency is a systems challenge, and it may be hard to point to any single reason for the differences. Tesla has been refining its cars for a decade so I would expect a next-generation I-Pace to improve.”

That’s Duoba in the picture above testing the efficiency of a Tesla Roadster in 2010. The testing was part of Duoba’s work to help develop SAE J1634, the auto industry’s recommended test procedure for measuring energy consumption and range for EVs. It’s fascinating to learn how the test process works. The range calculation starts with assessing the usable energy in an EV’s battery pack.

Efficiency is a systems challenge.

Electric cars are put on a dynamometer – rollers that spin the wheels in a lab – and run for about three to five hours through a succession of drive cycles that approximate a combination of city and highway driving. As the battery reaches depletion, the vehicle’s wheels are spun on the dynamometer at the equivalent of 65 miles per hour until it can no longer maintain that speed. The test is then terminated, and the total usable battery energy is determined.

Then the vehicle is put on the dynamometer again, this time for two runs on the urban test cycle – a 23-minute simulated route of 7.45 miles with an average speed of 20 miles per hour. (This test cycle was developed more than 40 years ago.) The EV is run again on the dyno, going twice through a ~13-minute highway cycle of 10.26 miles with an average speed of 48.3 miles per hour.

Based on the number of kilowatt-hours consumed per mile in each cycle, you can derive the efficiency for city and highway. “The efficiencies coupled with the usable battery energy is how you calculate range,” said Duoba.

Once Again, Your Mileage May Vary

How similar are the 20-mph city and 48-mph highway test speeds to how you and I actually drive? Not much. Therefore the EPA applies a 70-percent adjustment to reduce the efficiency and range to a level you might realistically encounter in your driving. The .7 factor was derived from an analysis of testing and real-world efficiency for many gas car but, according to Duoba, works well for electric cars for both consumption and range. “If you live in California, your range may normally exceed these estimates,” said Duoba. “If you live in Minnesota, the estimates may be too optimistic.”

So the final range number might not be entirely relevant to your experience. But it still serves a useful purpose as a way to compare one EV to another. The same procedure is applied to all cars so we might deduce, for example, that the Tesla X is about 10 to 20 percent more efficient than the I-Pace.

How meaningful is that comparison? Well, in terms of your pocketbook, it might not make such a big difference after all because all EVs are incredibly efficient. The difference between the two levels of efficiency in the I-Pace and Model X as it relates to the cost of electric fuel for about 12,000 miles of annual driving is probably about $50 per year. Similarly, the impact on an average driver’s daily life based on an EV getting a range rating of 230 miles versus 290 miles will be slim. Both battery-powered cars provide a lot more range than most people commonly need. Regardless, the way you drive, like a saint or a speed demon, will have a much greater impact on the range than any differences in the vehicle’s technology or the estimated numbers offered by the EPA.

The bottom line for me is that all EVs are dramatically more efficient and less polluting than gas-powered cars. As long as a car gets more than 200 miles on a charge, let’s not get hung up on the exact range numbers supplied by the EPA. Drive the EV you like best.

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128 Comments on "Take Official EV Range Numbers With A Grain Of Salt"

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Problem is EPA tries to apply gasser metric to EV. When you lose 80% of energy as heat with ICE, environmental variations make little difference. EV being about 4 to 5 times more efficient, variations are dramatic.

This is why they should do graphs over speed rather than a number (or 3 numbers). In this day when everyone has internet access, graphs are plenty readable by everyone. Example graph I made for SparkEV below.


> When you lose 80% of energy as heat with ICE, environmental variations make little difference. If X involves 20% more work (energy) than Y, a vehicle that is 100% efficient will use 20% more energy doing X — and so will a vehicle that’s 1% efficient. The *absolute* difference will ge greater the less efficient the vehicle is, but that’s obviously not what you’re on about, because that would mean the inefficient ICE has “more dramatic variations”, not the efficient EV. Inefficiency alone then is not why ICE range varies less between summer and winter. If we didn’t have any use for heat, We heat the cabin when it’s cold and that does require energy. It’s true that in an ICE, the heat that is just waste when it’s warm can be used to heat the cabin, whereas in an EV you must either create it (resistive heat, basically panel ovens) or pump it from outside (like an inside-out refrigerator). The first method can really make a big difference – my LEAF’s heater can consume up to 4.5 kW, whereas driving consumes something in the ballpark of 12 kW on average. So up to a third of total consumption… Read more »

Ah, but in the cold the air is more dense so more goes in cylinder.

I had a bike in the 80’s that’d go about 5 mph faster wide flat out if temp was around 40.

It is important to remember that the MPGe (It is miles per 33.7 kWh) number provided by the EPA is based on gross electricity input into the car and includes charging losses which can be quite substantial. I don’t know what kind of charging they base this on though I would guess it is 240 v AC. DC charging may have smaller losses though a fair comparison would include the losses from converting the utility supplied high voltage AC to DC at the charging facility. To make a meaningful comparison between EV and ICE you must must look at the mix of sources supplying the electricity and include the thermal efficiency of any power being produced by heat engines, mainly coal/steam (about 35-40%) and gas (up to 60% for dual cycle). Nuclear (20% of US electricity), geothermal and solar thermal (both tiny) are heat engines but produce only tiny amounts of CO2 (from construction, staff transportation, fuel fabrication, etc.) so are special cases. PV solar and wind aren’t heat engines. Transmission and distribution losses need to be taken into account also. ICE cars vary a lot in overall thermal efficiency with the Atkinson cycle engines used in the Prius and… Read more »

“DC might have smaller losses”. Smaller losses on the window sticker? There won’t be smaller losses in any place that matters since a faster charge will not be as efficient as trickle charging overnight.

Faster charge not as efficient? You can’t make that blanket statement. The Leaf for example is very inefficient with a trickle charge. There is a 300W hit whenever charging – whether trickle or not. So that 300W all night long is a huge efficiency hit. That 300W hit completely dominates the losses compared to the extra heat with charging faster.

No, I am not making a blanket statement since obviously I realize the VOLT, ELR, or BOLT is more efficient at 1.3 kw than .95 kw. And tesla charging systems take about a 30% penalty in efficiency on 115 vs 190 or higher, why I’ve never found out. It is possible that the new 48 and 72 amp chargers in the Latest Tesla products DO NOT have this penalty, but it is hard to know since I haven’t seen anyone measure this on TMC or here lately, and Tesla discontinued 120 volt charging times on their ‘time calculator’.

I’m saying that 50 kw charging is in every case less efficient than level 2 charging for the same vehicle. But you are not paying attention since I haven’t seen anyone use a 115 volt charging cord to do much DC charging on the Chademo Nissan Leaf port lately, which was stated in my first comment.

The whole EPA paradigm is old world and should be obsoleted.
EV manufacturers should be building in a plethora of factors into their range guess-o-meters, Especially with connected cars and route calculation, many factors are known such as temperature, wind direction, road type/speed, etc.
Then they could collect the real world actuals and post them on their website to provide prospective buyers real world examples of their efficiency / range in real world examples (i.e. update the on-line route planning tools to show what others are actually getting, vs some EPA prediction)

20 years of hybrid history. Study those attempts to address real-world. There are far more complicates than the typical consumer is willing to take the time to understand.

“typical consumer is willing to take the time to understand”

That’s nonsense. This is not rocket science. Rather than dumbing it down and present data that can vary by almost 100%, we should be teaching them and incorporate into driver’s license test.

We have been teaching! For the past 20 years there has been a serious effort to overcome those challenges. Haven’t you noticed how much the rating system has changed?

I have not noticed any change. It’s still just City and Hwy. What have they been teaching?

I would claim that all history is hybrid. 🙂

You seem to think car makers are in this to make the world a better place. By law, they are in this to make money for their investors. Not to improve anything else. Not to serve their customers. It’s in fact illegal to pursue such ends; these goals are only allowable as *means* to the goal of profits. A group of people can invest together towards other goals than profit, but then they have to create a non-profit corporation — that’s why this separate kind of entity exists.

If you think that by being honest and doing good a company can get Goodwill so people will buy their stuff, turning honesty into a good business, that reminds me of me twenty years ago. Turns out people don’t want the truth, if there’s a more beautiful lie available as an alternative. Elon Musk wouldn’t have got the attention of the world by soberly presenting the facts — he does it by presenting an exciting vision of a better future, just around the corner.

It might be useful if that was done by independent 3rd parties (the “honestjohn” motoring web site in the U.K. does this) but there’s no way a manufacturer should be trusted to collate such figures “hey Brian you should get the new VW Neo, the VW website says it will do 700 miles based on customer input “

ICE and electric both suffer range reduction from environmental effects and I’m not sure they are much different as a percentage, but of course for different reasons. It is very common to take a 30-50% hit in range in an ICE on short trips in cold temps.
Btw, the 20% number is quite out-dated. There are lots of ICE engines in the 30’s percent efficient and the max tested ICE has 54% thermal efficiency (MAN S80ME-C7).

No, the average is still very low like 22% for the ICE thermal efficiency.

ICE efficiency increases with high compression. For the same compression ratio, the Otto cycle is always more efficient than the diesel cycle. But gasoline self-ignites at lower compression than diesel fuel (in other words gasoline is lower octane), which is why diesel engines can still achieve higher thermal efficiency. Less refined fuel like heavy oil can be compressed even more before it self-ignites. The example he reached for is a ship engine designed to burn heavy oil. It has very high thermal efficiency, roughly half that of any electric motor, but nothing in the design is useful to improve an engine running on diesel (which self-ignites in every diesel engine by design, and therefore cannot be compressed any more) or gasoline (since the Otto cycle becomes LESS efficient if the fuel starts self-ignites, in addition to damaging the engine). And with high compression comes particulates; ship engines like these produce enormous quantities of NOx compared to ordinary diesel engines (thousands of times more). In short, the existence of internal combustion engines with over 50% thermal efficiency is completely irrelevant to the discussion of cars. Yes, I’d weigh only 20 kg on the moon, but I still really do need to… Read more »

The lower efficiency of the ICE gives you more waste heat to use as free cabin heating, which means using cabin heating will not impact your range like it does in an EV. I believe that’s what BoltEV was trying to say.

Yes, that’s what I’m saying, but it’s more than just cabin heating. Thermal engines run more efficient the higher the temperature differential. With ICE, you have 80% waste heat that can be leveraged whereas EVs have practically none (or literally none other than some Teslas).

I’ve certainly seen some EV bashers try to claim, contrary to all facts, science, logic, and common sense, that, the massive energy inefficiency of an ICEngine was somehow an “advantage”, but this is the first time I’ve seen someone who appears to be an EV advocate do that!

Gasmobile makers have had more than a century to “leverage” the waste heat to use it for something useful other than cabin heating. The fact that they have not succeeded should be a hint, Sparky!

If there was a way around the limitations of thermodynamics, then we’d all be using perpetual motion machines to power our cars.

If gas engines do not use the waste heat to up the engine efficiency, they’d be getting about 20% less efficiency. Consult Carnot (not Carnac the magnificent) if you don’t know what this means.

Thanks, but I read up on Carnot efficiency long ago, and several times since.

On the other hand, you don’t understand what “waste heat” means. If it can be used to increase engine efficiency, then it’s not waste.

Carnot efficiency increases with an increasing difference between the hottest and the coldest parts of the engine. That doesn’t mean that there is any magic way to use waste heat to perform work. If you could, then by definition it wouldn’t be waste heat.

By your logic, gas engines are 100% efficient, because the heat is used. Total nonsense.

Wrong again. Electric motors aren’t thermal engines. So they wouldn’t benefit from heating up, and we don’t need to spend any energy heating them just because it’s cold outside.

EV are not only electric motors. Think why EV efficiency is low in low temperature. There’s no waste he that can be leveraged.

As an aside, there is no “free cabin heating” in any vehicle.

Every time you full up a gas vehicle you put in 2-3 gallons of gas to produce the forward motion, and then 7-8 more gallons of gas to produce heat and light. You buy the gas, the engine produces that heat, every tank, every mile. It isn’t free, and it greatly reduces the range you would otherwise have with a tank of gas if you weren’t producing that heat.

In the winter you divert some of that heat to warm the cabin, but you pay for that heat no matter what, whether you use it or not.

With an EV, you only pay for the heat you actually use to heat the cabin, not all the other heat too. And it only reduces your range when you turn on the heat, and not all the time like in an ICE car.

True, just like there is no free charging, there is no free heating. One always pays for it, used or not.

20%+ for ICE is run in optimal conditions. In the real world, best they muster is about 20% when you have stop-and-go (no regen).

How many concepts are you going to confuse in one thread..? Stop and go doesn’t affect efficiency (how much of the energy used was doing mechanical work), it increases the amount of work. Consumption may be what really matters, but it’s not the same as efficiency, and it cannot be measured as a dimensionless percentage.

How far detached from reality are you? If you think stopping doesn’t waste energy, you need to study basic thermodynamics. Fact is, even EV is less efficient when speed up and slowing vs constant speed.

There are lots of ICE engines in the 30’s percent efficient and the max tested ICE has 54% thermal efficiency (MAN S80ME-C7).

You’re talking about bench testing with the ICEngine run at its most efficient RPM speed. You are not talking about the efficiency that a gasmobile gets in real-world driving, which — as Ffbj said — has an energy efficiency percentage that still averages in the low twenties. (That includes all mechanical losses, not just losses in the engine.)

For EV electric motors, the difference between energy efficiency at their most efficient speed and the average running speed in real-world driving is a rather small difference.

And you are just guessing wildly what he is thinking of. You imagine you can know the motives and thoughts of everyone else as usual!

If you’d bothered to look up the engine, it’s a heavy oil engine for cargo and tank ships. Heavy oil doesn’t ignite easily, so it can be compressed A LOT, and that means thermal efficiency goes up, although not nearly as much as NOx and other particular emissions.

No diesel engine can get close to 50% thermal efficiency at any RPM in any circumstance. The upper bound is much lower — under 30% if I recall correctly.

That is just not true, stationary ICE’s get quite a bit over 50% thermal efficiency even before heat recovery actions.

Yup, large marine engines develop better than 50% thermal efficiency, better than any of the smaller engines found in automobiles.

Terawatt is displaying his ignorance again. Sadly, that’s a pretty common habit of his.

Dude, I didn’t need to look it up to know that the most efficient ICEngines are large marine (ship) engines, which gain efficiency from their larger size, which helps with Carnot efficiency among other things. Didn’t need to look that up because I already know that. I generally don’t try to cram everything I know about a subject into a single comment.

You’re projecting your own ignorance onto others, just as you did the other day when you accused Elon Musk of lying about plans for commercial suborbital space flight.

You manage to combine ignorance with an assumption that you know far more than you actually do about a given subject; combining ignorance with the Dunning-Kruger effect!

Perhaps when you grow up, you’ll learn to listen and read more, and talk less about subjects on which you are ignorant.

Good point, for short trips the ICE range probably varies even more than EV range. I agree that the 20% figure is outdated, but 30% is the state of the art for engines that can be used in a car — not 54% as you try to give an impression of. It’s hard to see how it was tested, since according to Wikipedia it hasn’t been built: “If the largest version is ever built, it will be the most powerful piston engine, with more than 136,000 brake horsepower (101,415 kW) in Mk-9 version. The cylinder bore of the internal combustion engine will be 1,080 millimetres (42.5 in). It will be used in new container ships of more than 10,000 twenty-foot equivalent unit (TEU) in order to achieve around 25 knots (46 km/h; 29 mph) cruising speed. The thermodynamic efficiency of the engine will surpass 50%.[1][2]” https://en.wikipedia.org/wiki/MAN_B%26W_K108ME-C In any case, a 14-cylinder 2-stroke heavy oil engine with over ten thousand liters displacement and horrendous emissions of NOx may achieve high thermal efficiency, but pulling it out of a hat to demonstrate how great ICE can be in the context of discussing cars isn’t just disingenuous, it is dishonest in the extreme.… Read more »

Toyota’s 2.0 Dynamic Force Engine is 40% efficient and 41% efficient in hybrid form. Electric vehicles are 85-90% efficient. True, EV’s cost less to run, but their high prices and expected higher depreciation make the savings per mile irrelevant.

Again – comparing the 2 efficiencies is Apples and Oranges since the power -in / power out of electrics is an extremely small part of the entire picture.

Example – Electric Heat is always 100% efficient. If so, why don’t all you guys have electric baseboard heat in your home and throw out your gas or oil or propane furnaces – since Electricity is SO EFFICIENT?

Practical reason #1: You don’t want to pay the resultant electric bill. Now why is that?

It has always troubled me that these dyno tests only test drive train efficiency and ignore aerodynamic efficiency. If drive train is all that goes into EPA numbers than why do auto manufacturers care about designing aero cars? I fully understand aero will lead to real world improvements, but auto manufactures generally design to the regulations not real world performance. Please shine some light on this for me, thanks.


Air resistance is used as a coefficient.

They use fans to simulate the airflow. ICE vehicles would overheat if they didn’t, since their radiators need a lot of airflow in order to get rid of all that wasted energy!

Most engines have propeller fans near the radiator. You must be smoking the same stuff Pushi is lately.

Be untroubled. They measure aero drag in coast down tests and program the dyno based on the results.

They account for all losses. It troubles me that you got so many up votes from people that think the same.

This is how it works: The car is driven to about 75mph, put in neutral, and allowed to coast on a level road. The speed/distance is measured over time, and using F=ma, you can figure out the force imparted to the car from all sources (air drag, road loss, etc) as a function of speed.

During the efficiency test, the dyno then applies a resistance force to the tire that equals the sum of acceleration force (at the test cycle’s current acceleration) and the force from the above measurements (at the test cycle’s current speed). There’s also a correction to not double-apply any losses (i.e. rolling losses from being on the dyno).

It’s a great test if done right. However, if manufacturers cheat with the data put into the dyno, they’ll get a BS result.

Yes, one of the reasons why a couple of car companies got in trouble for reporting too high of MPG ratings was that they were cherry-picking their best coast-down test results for the coefficient. That meant all their results were skewed high, as if they were more aerodynamic and had less rolling resistance

I suspect he got many up-votes from people who had the same question. I have been wondering about this for a while, and am very happy to have it answered here 🙂

I don’t understand how they could possibly separate aero drag from rolling resistance in such tests. At best, if they’re depending on coast-to-a-stop tests, it still has to come down to an estimate of Cd.

“…these dyno tests only test drive train efficiency and ignore aerodynamic efficiency. If drive train is all that goes into EPA numbers than why do auto manufacturers care about designing aero cars?”

Aero drag is estimated rather than measured in an wind tunnel, I guess because it’s simpler and easier that way. It would be nice if they would do actual wind tunnel tests rather than just making an estimate, but the EPA’s energy efficiency and range tests for EVs seem to yield results reasonably close to real-world averages. Certainly the EPA ratings for EVs are far closer to reality than the ratings given in Europe, Japan, or China; so it seems the EPA estimates are — literally — close enough for government work! 😉

I believe the correct way to say this is that aero efficiency is not taken into account as much as it should be. This thread taught me a lot but a coast down test has its average speed closer to 35 miles per hour. What is important is aero at 70 mph – not 35. Sure there is a relationship but a car with 1/2 the aero resistance will not have twice the coast down. At 70 mph – aero dominates. At 35 mph, it does not. And probably the average speed with a coast down from 75 is more like 20 mph in a car with bad aero and good tires/drivetrain.

In what engineering world does a 75 mph coast down reflect reality?

Am I missing some correction factor? My recollection is that real world tests show that highly aerodynamic vehicles to relatively better than EPA at highway speeds.

No mention of the largest variable, weather! I regularly beat the EPA in my Tesla 3 but if it’s raining or really cold the consumption is much higher, 10-15%. I think this is mostly aerodynamic drag, cold air is denser than warm air, in the rain that air has heavy water in it(on the road also). Not that it matters much, with 2-300 miles you just don’t think about it much.

unless you driving in CANDU reactor pipes system there should be no heavy water 😉

f rom what I’ve read it’s mostly to do with the work needed to expel water from the tyres. Water is quite heavy and all that water on the road under the tyre needs to be pushed out if the way otherwise the car would aquaplane.
Whilst the air is indeed heavier with raindrops in it it’s a fractional effect that isn’t large enough to make any real world difference, it’s down in the thousandths.

The weather is different in all locations, how many numbers should be listed on the sticker? 1 million? 1000 millions?

I get a real world range of about 230 miles in my Model 3 Performance…. before Winter.

In Finland I get around 200 _km_ in Model S 60 during winter. It’s pathetic. My little gas car gets 600-700 km.

The “pathetic” range of a BEV in winter is still not nearly as pathetic as the energy efficiency your “little gas car” gets.

If maximum range without refueling/recharging is what’s most important for you, then by all means stick to a gasmobile. For almost literally every other criteria and characteristic, the BEV is far better.

I get around 110 km in my my13 leaf with 17KWh left on the battery. Maybe winters are a tad warmer in Denmark 😉

Move to a human friendly climate. Or just keep your driving to under 200 km!

Or just drive a gas car like everyone else on this planet..

Yes. 100 kWh is in my opinion the absolute minimum for any practical car.

I hope my dad isn’t this crazy

100 kWh gives you nearly 375 miles of Hwy AER in most BEV’s. That is a bit of overkill. 60 kWh gets you around 230 which isn’t bad given the rapidity with which DC Fast chargers are showing up, and the speed with which they can get your car from 10% to 80% of capacity. I think going forward that BEV’s will work best with 70 kWh or more, but 100 kWh is simply more than most will need or want. As chargers get more common and charging speeds go up, roadtripping in a BEV will become little more work than roadtripping in an ICE today and huge packs aren’t needed.

You’re a horrible driver:). I get 350 in my RWD.

It would be nice if they had a published winter effiency at 75 mph. While not an issue for the SoCal drivers, it has a big effect in the Midwest. An example I was considering taking a day trip of approximately 280 miles round trip. I have access to dcfc roughly 60 miles from home and a 12a at 208 (2.5kw) l2 at the destination. I will be at the destination for approximately 8 hrs. Problem is it’s going to be snowing and cold, the whole trip is between 55 and 75 mph. Also an elevation change of 2000 ft. I am fairly confident I can make it one way as its down hill, but I am not sure I can make it back. In the summer I can do the trip with only a 20 min stop at the dcfc. I expect I can get 3 ish m/kw going vs the 4 during the summer, so approximately 46kwh to get there, then add back 20 kwh at the destination, I might just make the dcfc station to charge up for the final 60 miles home. That 60 miles is tough as its. Both fast and uphill. I usually figure… Read more »

What would they publish?

I live in Minnesota. Here, we don’t call what others define “Winter” to the same way. We have snow right already. That’s what we call “Fall” though, hardly a representation of what our commutes are in January. Yet, that’s the norm for others during their cold season.

Right. Cold weather performance would be too variable for a single number to be meaningful. You may get significantly different numbers depending on how much cabin heating you use, what speed you drive at, whether you start with a cold or a warm battery, and whether the region you live in considers “very cold” to be 40 degrees or -10 degrees.

Generally speaking, people report a 20-30% range loss in near- or sub-zero conditions. But it can be worse if driving for an extended time at low speed, because a longer trip likely means more loss from cabin heating.

So have three then instead of two. If you know roughly what to expect at -30 C and 5 C and 30 C, you’ll cover almost the full gamut, and by simple interpolation roughly what to expect anywhere in between.

How much range you lose when it gets cold does vary a LOT between different cars. And that variation is of interest to many. At the high end it’s not really as interesting — there it’s more about capacity loss/cycle life….

I named four variables, and you’re suggesting that could be covered with just three data points.

Clearly math is not your strong point. In fact, it seems that your only strong point is displaying ignorance on any and every subject. 🙄

You are a perfect candidate for a GM Volt.


If that was aimed at me, I do have a volt in the household as well. I much prefer the Bolt for daily driving as the Volt has a winter range that does not support my daily commute of 52 miles on electric. Effiency for both cars is similar and now that it has started to get cold instead of taking 13 kWh for the daily drive it now takes 18+. On really cold days the Volts range is only 30 miles or so on electric. In many ways the Volt is a better car and if it had a 20 to 25 kWh pack it would be the perfect car. But with only 14 kWh usable the AER rage is too low. Also the drive programming is far better in the Bolt.

Hit the DCFC on the way there. Then you’ll have more charge when you arrive, and thus more when you leave for the return trip. It sucks to have to charge on the way there for the trip back, but at least it’s an option.

Range can drop dramatically in very cold weather – up to 40% from the graphs I have seen. So in order to have a 200 mile range in winter in Minnesota, the advertised range would need to be 333 miles.

When EVs become more universal and there are lots of used ones to be bought, battery wear is also going to be a factor. For the same electric car to have a 200+ mile range throughout its entire operational life (down to 80% of initial capacity) in seasonal extreme conditions, it would need to start with an estimated range of 417 miles.

In Minnesota, traffic patterns can dramatically during the winter. Travel time can more than double. That level of variance isn’t informative. We know that for a fact too, since EPA always published a range and most people ignored those numbers… focusing entirely on the big one.

I would be happy with a rating at say 20f and 75 mph. That would give a decent idea of what range will be in winter driving. Sure it will be less in snow, but I won’t be taking road trips when it’s snowing.

Imho the whole idea of not publishing battery sizes and going by range only is a bad idea. Range is so environmentally influenced that it’s only useful in comparing cars in a general sense. Battery size gives me a better idea on how far I can get on those bad condition days. I know the Bolt gets about 2m/kwh on those days. No way it can do a road trip, but it still offers enough range for my daily commute. My gom is showing about 145 mile range now using hilltop reserve. Down from 200 over the summer.

This is why there is room for PHEVs for quite some time yet. It also explains why Canadians seem to have a much higher preference for PHEVs than their southern neighbours.

I don’t know about Canada specifically — but pretty much all numbers I have seen thus far suggest that BEV vs. PHEV preferences in various markets are almost entirely a function of incentive systems: where PHEVs get the same amount of incentives (in spite of being cheaper and offering less environmental benefits), there is usually a fairly strong PHEV preference; where BEVs get larger incentives, they generally get the upper hand.

Yeah, and usually you quick charge up to 80% only..

Hihi, my six year old LEAF has about 78% remaining capacity. And loses 40-50% of what it still has when it gets really cold. And displays the low battery warning at 30% SoC. Which means the anxiety-free range is fast approaching zero!

But I agree and applaud this kind of thinking. To find the “reasonable lower bound” you take the “reasonable worst case” conditions and combine them with “reasonable worst case” degradation.

One should compare that lower bound with one’s own normal driving pattern to see if a car fits. For me it doesn’t matter if KONA’s winter range is a lot less than in summer, because I don’t want to travel far by car in the winter anyway. (Maybe some day I will, but rare exceptions should have no bearing on my choice of car — far better to adapt my behavior as required in the exceptional case than to compromise the 99% to allow for corner cases.)

Worse efficiency affects more than just cost. For a given number of miles, it increases time to charge and it adds wear to the battery, because more cycles are required.

What ai really am missing in the summary:
I do not care at all about the few $ $ more I have to pay in the iPace.
What really gets me thinking ist the difference in miles I can CHARGE per minute aconnected to the (super)charger.
That is more important than 235 or 260 or whatever miles of range.

Most charging is done at night while you sleep. Fast charging is only needed on trips. Fast charge too often and you’ll need a new battery in a few years. Longer range means your battery will see fewer charge cycles per year and will last longer.

Bauer might be thinking about long distance travel.

Range is not important in long distance traveling?

One size does not fit all. YMMV: Your Mileage May Vary.

Okay, you don’t want to take any long trips in your BEV, so the speed of charging isn’t important to you.

Other people have different priorities. Amazingly, many people think the speed of fast-charging is very important in a BEV. If they didn’t, then nobody would care about Tesla’s Supercharger network. Since lots of people do care, it’s an important selling point.

I agree with the conclusion that for the average person the difference between the I-Pace and the X will not make much difference.
The kicker with EVs is with the long distance drives. Once your trip gets over about 150 miles the drivers of these cars will have a much different experience.

They are similar enough with respect to range that the many other, big differences between them should be far more important when choosing between them.

This discussion topic is loooong overdue for plug-in vehicles. Real-World efficiency verses estimated values have been a major problem for hybrids over the past 2 decades, but few seemed to recognize that same impact would affect users of plug-supplied electricity too. Slower driving and the need for cabin heat during the winter, combined with the usual losses related to cold batteries should have been an influence often mentioned. Instead, there has been barely a whisper, despite being such a major factor to consider when comparing various designs. When it comes to speed & power, I’ve been laughed at for pointing out “electricity guzzling” as a concern. Only now some are starting to recognize the problem that creates when waiting for your pack to recharge. You need to do that more often and it takes longer when the system is less efficient. Simply adding more capacity brings about problems. Look at how expensive that made Volt, Giving it enough to deliver that “40 mile, all condition” range goal made it unable to compete directly with traditional vehicles… rendering it a niche, rather than being the next logical step in electrification. That’s why the other automakers are trying to squeeze out greater… Read more »
I partially agree, and I’ve certainly come to appreciate this aspect of efficiency more over time. But I still think that most people will have much more range than they usually need, fast charging en route will be something we do a few times per year, and therefore whether it takes 20 or 50 minutes will not be something we care a great deal about. But if you look at this from the infrastructure PoV it looks very different. Just imagine if it took half an hour to an hour to refill an ICE, but everyone tanked at home except for a few long trips. How would the lines look at gas stations around Christmas and Easter..? And if we went there only once or twice a year, could that support this many gas stations? The infrequent use, long time, and likely enormous difference between peak demand and average demand makes the infrastructure economics very different. Once there’s enough stations to give good “geographical resolution” (we can go “anywhere” without making significant detours to charge) it will be cheaper to use stations more efficiently during peak demand, i.e. charge faster, than to keep adding stations. That’s why all providers are… Read more »
Do Not Read Between The Lines

DCFC charging time!

That is all.

You can give a driver some kWh, but you can’t tell them how far it will take them! YMMV…

How? That distance varies dramatically depending upon your speed of travel and climate setting, not to mention the influence of wind. Estimates would continuously to be adjusted, even for something as basic as a morning commute.

Or, to be more succinct: YMMV. Which is what he said.

The important thing is that they use the same standard for all EVs. The i-Pace is less efficient than the Model X. You can try to rationalize that away any way you like.

A Dyno is the a Most Unreliable way to calculate Fuel mileage, Because , There Is “Zero Drag” The Car is at a Standstill Only Spinning the stationary Rollers … Take 1/3 + a Bit 0ff of the Resulted readings & it would Be what You’d Get In Reality..

It’s amazing how you can come to an utterly wrong conclusion when starting with correct — but woefully incomplete — facts.

Why Not Give it To Us, Complete the Puzzle…My Car Was Dyno’ed & That was The Conclusion that was derived ..We Got 1/3 + More Miles Than I Got, In Real World On the Road Driving..

You know what you are talking about but he doesn’t even though you stated the issue clearly. He’s good at criticizing others even without being conversant with anything.

Poor Bill. He’s so jealous that a guy who doesn’t even own an EV understands EV engineering better than he does! 😆

Jealous? hehe – well If I truly have less understanding than you do then I must be having trouble being smart enough to autonomously know how to inhale and exhale – I must have a negative IQ.

Naw, I don’t argue with everyone as you do, since I’m not Jealous…. For comparison, I’m not Jealous of that piece of used Toilet Paper that gets flushed down the toilet – of which although I consider it much more useful – I’m not jealous of the function it performs, nor argue with it.

1. Because the EPA range estimates are not dependent only on dynamometer measurements; they also factor an estimate of aero drag into the equations. This has already received quite a bit of discussion in comments above, so why should I need to repeat it?

2. Just because your car’s real-world range is 1/3+ less than the dynamometer tests, doesn’t mean that all cars do.

I bought a MY 2016 Spark EV in 2017 and did a bit of long distance driving shortly after I got it. The Spark has an EPA range of 82 miles per battery charge with its ~18.5 kWh battery. After a 99-mile drive from Ocala to St. Augustine, Florida at no more than 42 mph over rural roads on an early Sunday morning at balmy temperatures I still had 22 miles of range left at the destination.

That’s very interesting. The graph in my blog post shows about 120 miles range at about 42 MPH, and you hit that right on the money.

Not surprising you beat the EPA range estimate if your average speed was <42 MPH. People driving long distances usually average much faster, near freeway speed.

Another Euro point of view

Our IT guy in Geneva has a Model S75D. He yet managed to fully drain his battery in mountain winter spirited driving in about 100 miles.

By looking at the range chart in the Model 3 owner’s club and figuring “spirited” driving would be around their 80 miles per hour range, then subtracting 40% for winter, his range should have been closer to 125 miles. I guess it was the mountain part that made up the additional battery demand to reduce range to 100 miles, but still that must be exceedingly rare to be driving that fast in conditions that extreme.

In central and southern Europe (Germany, Austria, Switzerland, France and so on) a large part of the highways are rural, with >5% gradients on large parts. Try doing 80mph with 4 passengers on the way to your ski trip in France, and see how close to 100 miles you get before charging is required 🙂
Just pointing out that for large parts of the world, PHEV’s seems to be the best solution in the near future.

Glad to see so many companies developing EV’s but until they come up with a 10 minute method of charging, I’ve to to stay with my Chevy Volt. I never know when I’m going to take a cross country trip and I just can’t stand thinking I could be stranded in the middle of nowhere. EV drivers: have you ever run your batter low and forgotten to plug in? If so, you’re going to miss that appointment or, worse, miss work that day.

Like combustion cars never get stranded…

No, but a 2 gal can of gas can get you to the next fill-up, which then only takes 10 minutes to get you another ~400 miles.

It can. What it cannot do is be sustainable. Fossil fuel is generated by mother nature, but we’re using the stuff at roughly a million times the rate it is created. It cannot continue indefinitely because math, so it doesn’t really matter whether you like it. Combine this with climate change, and it seems only stupid to put off solving the problem as soon as we possibly can.

And not getting stranded is fairly easy for most people almost all of the time. Just pay attention to what you use and what you’ve got left, and plan conservatively when undertaking trips that require planning.

When you weigh both the advantages and the disadvantages, hybrids are the worst option. Plug-in hybrids can be better in theory, but aren’t really in practice. BEVs are best overall, economically and environmentally. And even with respect to time. You will spend less time waiting for your EV to charge than your gasmobile to fill up, because your typical week will require plugging in once, at home, and unplugging again the next day, costing you less than ten seconds.

I have. I could have taken the bus, but instead drove two minutes off the highway, parked at the fast charger, plugged in, went inside the supermarket and got some breakfast, ate it, unplugged and drove to work, arriving about twenty minutes later than planned but well before nine, when I’m supposed to have arrived (we have “core time” from 9-15, so work 7-15 or 9-17 or anywhere in between). If I had planned to be there nine I would have had to send an SMS to my boss to say I was running late, but the world probably would have continued to spin even then.

I am very confident that this statement is not typical “I never know when I’m going to take a cross country trip”

The majority of people do not wake up on a random Tuesday and drive across the country. And you know what, the majority of people have never driven cross country. I happen to have because I was moving from NY to CA and then back. I didn’t have a lot of money and I had a car so I drove it.

I have forgotten to plug in. I realized it early in the morning and stopped by a QC. I was not late to work. The vast majority of days, I have a huge buffer so forgetting is not a big deal. A 10 min QC will get the vast majority of people to work even if the battery was pretty low. My 70D (one of the slower charging Teslas) gets about 50 miles in 10 minutes. The closest QC to my house is a Chademo so it is significantly slower – but still 10 min would get most people’s daily commute.

Coming up on 6 years of EV only.

Models S and X will probably get a range increase when battery packs are upgraded with 2170 cells.

A key differentiator for road trips is the charging time. And that is greatly affected by efficiency as well as the charging rate. If a car ends up being 20-25% less efficient at 70 mph than another and both DCFC at the same rate in terms of kW, the mph charging is 20-25% better on the more efficient car. The I-Pace falls down on real world EV usage except as a metro commuter. It doesn’t have fast enough AC L2 nor DCFC.

The EPA measures three roll-down coefficients: “Target Coef A (dbf)”, “Target Coef B (lbf/mph)”, and “Target Coef C (dbf/mph**2)” on a ‘Standard Day’, ~70F no wind. These three are what it takes to calculate the power needed at any constant speed for any car, gas or electric above ~25 mph. Only two easily measured or calculated factors are needed, drive train efficiency and vehicle overhead to complete the model.

The drive train efficiency is driven by the engine or electric motor efficiency. Using the specific fuel or electrical consumption for any given power, you can easily plot the fuel or electrical consumption as a function of speed … except at speeds under 25 mph. Below 25 mph, you need to add the vehicle overhead, what it takes to keep it running or ready when parked. This makes a performance curve that adjusted by several benchmarks, you can predict how much gas or electricity it takes to go any distance at any speed such as this graph for the Prius Prime:

The air density changes with temperature and affects consumption above 45 mph. Other loads like heaters and air conditioning can easily be added. So an easier rule of thumb:

~30-35 mph – use the City number
~65 mph – use the Highway number

All high school math and physics, this may still be intimidating. But it starts with the three roll-down coefficients, drive train efficiency, and overhead load is all it takes. Then use three benchmarks and the problem is solved.

EPA range estimates for EVs are getting more accurate. However they aren’t quite there yet. Another factor people forget about is range is all about energy management. Someone used to driving an ICE is going to manage vehicle system energy very poorly when they start driving an EV compared to an experienced EV driver.

Where to start? Ok, the lab’s ‘7% increase in driving efficiency’ and 10% increase in powertrain efficiency (or less losses) doesn’t with any specificity tell where the problem is – (they certainly could do that), Certainly looks to me like Jaguar was overemphasizing performance and not caring very much about efficiency at all. The red roadster in the pic above had horrible efficiency when driven hard, but not bad if driven with a light foot. None of these ‘analyzers’ are from cold locales since no one has talked about Vampire Drain with the ‘x’ lately, – especially how it is in cold weather; and I haven’t heard boo about the subject in the I-pace even if it is to say (maybe) it doesn’t have any. As far as the ICE efficiency question goes this is still the same old myopic examination as I’ve mentioned a dozen times. But one point in all the point/counter point that has been missing in the entire discussion is that, in practice, a plug-in hybrid using jacket heat is much more efficient that a plain old ICE since the cabin heater gets to recoup a far greater percentage of it – in medium efficiency vehicles… Read more »

Saying “range numbers are a good way to compare EVs” is like saying “a hammer is a good way to build a house”. It isn’t a way at all, but it is a useful tool out of many when comparing EVs.

Oh C’mon Terrawatt that is just the way you view things, – since I and many others for very practical reasons have to view things differently.

I like to get between point A and point B as uneventfully as possible. I had to do a 200 mile round trip yesterday, and although having stopped exactly twice (event 100 miles away, and then dinner with friends later), there were ZERO recharging facilities of any kind, even an available ‘domestic outlet or power point’, what we call here a ‘110 receptacle’.

My Bolt ev has lately made many trips where at the end of the day I had between 5-10 miles left, and that is with Frugal use of the heater so that I would complete the trip. Of course if the available range of the car was even 10% less it would be a BIG INCONVENIENCE to me, which, it is NOT. The 57-60 kwh battery was a BIG FACTOR in the purchasing decision.

The fact that my comment just said ‘different people view things differently’ is just another way of saying that:

“The views of Reasonable People may Differ”.

Not here though. If you disagree with any facet of the polemic then you get a negative vote. Which really hurts EV adoption among the possibly interested since they don’t want to be associated with such a closed-minded group.

That is pretty bad for the I-pace considering that the Tesla modelX is running on Tesla’s old battery tech from years ago.
Probably indicates why Tesla is not upgrading to the new form factor in the X and S. There is no point until the others catch up to their old tech.

Motor tech is probably more meaningful on this score than battery tech…

I think folks on this thread have covered the huge effect of air temperatures on range but tires and wheels also make a huge difference especially at highway speeds. IIRC Motor Trend put “sticky” tires on a Bolt and it took a >15% range hit. I know Tesla worked very closely with Michelin on the tires for the model 3 to eek out as much efficiency as possible.

Great discussion. FYI, Mike Duoba told me that the dyno is set with very specific settings to account for three losses: tire losses, bearing losses, and aerodynamic losses. The testing process and results indicate exactly what those are.