Infographic: FleetCarma – Cold Weather Fuel Efficiency – Electric Versus Gasoline Showdown

JAN 16 2014 BY STAFF 46

As FleetCarma states:

“When we released real-world data showing how the ranges of Chevrolet Volts and Nissan Leafs changed with plummeting temperatures we wanted to show not just overall trends, but how much variation existed from trip to trip.”

“This time we took it a few steps further. With this infographic, our analysis focuses not on the differences within electric vehicle models, but the differences between electric and gasoline vehicles as temperatures drop. We looked through FleetCarma’s real world database to find how much the fuel economy of each vehicle changes at and below freezing temperatures.  It is important to note that the specific numbers used in the infographic below represent aggregates.”

Check out FleetCarma’s superb infographic below:
Cold Weather Fuel Efficiency Infographic: Electric Versus Gasoline Showdown

via fleetcarma.com

 

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46 Comments on "Infographic: FleetCarma – Cold Weather Fuel Efficiency – Electric Versus Gasoline Showdown"

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LOL @ cold-weather range “shrinkage”

Yeh that was a great Seinfeld episode.

That is an awesome set of graphs!!!! Especially the Bottom Line Graph. That should be the headline. “EVs Save more money than ICEs in Cold Weather”

+10 karma points to whoever spots the labeling/text error in that chart…..

SLOPPY work

Don’t you mean “carma” points 🙂

Oh, and they messed up in the very first graph. “average reduction 0-18” on the left and “average reduction at 32” on the right. So the brown box on the top right should have the top & bottom text swapped. Now is the data / percentages also incorrect or just the label?

Thanks for pointing this out! We’ve updated the graphic with the correct labeling (The data/percentages were correct)

“EV PAYBACK IMPROVES IN COLD WEATHER”

Utter BS for the simple reason waste heat isn’t wasted from an engine, when cold. That report is filled with too much bad karma, to single-out any of its many errors.

Sorry, but where in the infographic did it say it was wasted? It just states that it takes more energy to create that heat no matter what kind of car you have, and it is cheaper to pay for the energy needed in an electric than it is an ICE.

I think that is the number one point Jeff. 75% of 3.8 cents per mile for heat may turn out to be less than 15% of 18.6 cents per mile lost on idling and braking loss. I would like to see the data on that but it makes sense.

I’m somewhat confused too. If EVs perform worse than ICEs the colder it gets, how can the cost savings go up?

Was thinking the same thing. I haven’t crunched their numbers but my guess is the cost is so low in the first place.

Not exactly, but kind like adding 10mpg to a vehicle that gets 16mpg makes a much larger difference than adding 10mpg to a vehicle that gets 40mpg.

I had never considered this before because it is such a drag when the EV loses energy in cold weather but here is the spin.
They EV “percentage wise may be worse” but “cost wise may be better”
I just through some percent out there but if the the EV goes from 2.6 cents to 3.8 cents and the ICE goes from 15 to 18.6 the cost is higher. That is the spin

Hey maybe that is the real reason gas prices go down in the winter.

Aha.. yeah it may be a percentage thing.

That’s exactly it. Increasing a big number (gas costs/mile) by a smaller percentage (24%) actually ends up having a much larger impact than increasing a small number (electricity cost/mile) by a bigger percentage (46%).

Same idea as saying that increasing the US GDP by 10% has a much bigger impact that tripling the GDP of Spain.

LOL… I really should have checked the GDP of Spain before posting that…

Correction: Same idea as saying that increasing the US GDP by 50% has a bigger impact than a 200% increase in the GDP of Spain.

As long as we insist on heating the cabin that is correct. Unless MIT’s ultra heat pump comes to fruition we have to start seriously thinking about other ways to heat the EV. Driving habits aside, it is the number one loss of energy for the EV. For the ICE, it is a byproduct.

@pjwood: You can’t extract 100% of the waste heat of an ICE to heat the cabin. If you could, just leave the heater on in the car and you have no need for engine coolant. (Not to mention things would get QUITE toasty in the cabin…)

“Utter BS”? Why? Because you can’t do math?

Heat is fully factored into there. That’s why EVs running cost increases 46% when it’s ultra cold and gasoline cars’ running cost increases 24%.

But you don’t measure payback in percent. You measure it in dollars.

Ultracapacitors do not get affected by tempreture as much as batteries.

Fleetcarma can fix the graph but the factual spin is brilliant response to the cold weather argument.
The “percent” of savings is worse but that “raw savings” is greater. Brilliant!
http://www.youtube.com/watch?v=3DPKf7y1F-Q

Why do EVs have a much bigger tire loss than ICE?

I’m confused too… you could say that worse tire performance effects the ICE in just one way (accelerating/maintaining speed) and the EV additionally with worse regen. But that shouldn’t even double the number, here it’s more than tripled…

Tyre losses are a bigger percentage of the much lower overall energy consumed per mile in an EV.
Other drivetrain losses are more important in an ICE.

This might fool Southern Californians, but who is paying FleetCarma for the result they want?

My Roadster goes from around 240 miles in the spring to 60 miles in the cold winter.

My Volt goes from 42 miles in the spring to 6. So who is kidding whom?

There is nothing wrong with either car. I would see any ICE car would beat these #’s, in fact the Chevy volt does itself when you allow the engine to run.

I find your claim of a drop in range from 240 miles to 60 miles and 42 miles to 6 miles a bit difficult to believe. With the Volt, I suspect it fires up the ICE largely to provide heat.

Bill, I have come to find you as being rock solid in your facts (especially when it comes to electrcity) I read all of your recent posts. I did not jump in for I could add nothing to your electrcal arguments.
In the above please tell the temps where 6 is happening. 42 miles on the Volt in good weather is exactly my number too. I see it fall to low to mid 33 miles at freezing, 25 miles in the mid 20s. I don’t get the weather that you and my brother get in up state NY so tell us the temp in which you get 6.
Here is the “a hah”. I have always said the ICE would beat the EV in cold weather and as a percentage that is true. Watching your range go from 42 to 25 feels terrible and watching it fall only 20% in an ICE has been dismissed as better. The “a hah” is that the ICE is 4x more to begin with and 20% of 4x still cost more. It’s a spin but a truthful one.

double negative edit button

IN a rush hour situation in bumper to bumper traffic with the mandatory defroster on high in humid weather I get 6 miles in the Volt, and 60 in the Roadster. I’m sorry if people don’t like it but thats what I get.

In the moist, cold winter time, 100% defroster use is Mandatory to see out the windshield. Seat heaters don’t do a thing. BTW, 32 degrees is HOT in the winter time here and is almost never seen.

The point is, electric heaters and batteries don’t really mix. iIn the winter time here almost all the battery juice goes for heating, some to the battieries themselves but mostly to the cabin.

I hesitate to mention this because it will be seen as my most critical Tesla post to date: In stop and go city driving, I can usually recover 20% of the energy back to the battery. But only if it is over 32 degrees. Once the battery mass (that big black case behind me) in the Roadster gets under 32 degrees, the second BIG operational BUG presents itself.. A Primer on Roadster Regen: If the battery is more than 90% full, the system will not allow the battery to recharge and will turn on the ‘noregen’ light. However, if the heater is on high (drawing 9 amps at 300 volts or so), the car will regenerate 4 horsepower into the heater, and if you back off the gas soon enough when coming to a stop light you get more and more braking power since 4hp at 40 mph is nothing but 4 hp at 10 mph is alot of torque. Mechanical , winding, and rectifier losses make the braking effect more like 5 horsepower, but I didn’t want to confuse the issue with the truth, so to speak. EXCEPT when the battery is under 32 degrees, then the no regen… Read more »

Living here in Canada, I’m still getting 20+ miles of range at 0 degrees. 6 miles??

Six is like, what, 20 below zero, full auto defrost and 80 degree cabin driving through 6″ of snow on 20 psi tires?

Impossible to understand 6 miles in the Volt. I’ve rather impressed myself getting 19 one time at 5F. Driving fast with heat on Comfort at 75F. Do tell how to get 6 miles.

repeat of a previous post. Find the first one and read the subtending posts for a more complete explanation.

“…IN a rush hour situation in bumper to bumper traffic with the mandatory defroster on high in humid weather I get 6 miles in the Volt, and 60 in the Roadster. I’m sorry if people don’t like it but thats what I get.

In the moist, cold winter time, 100% defroster use is Mandatory to see out the windshield. Seat heaters don’t do a thing. BTW, 32 degrees is HOT in the winter time here and is almost never seen….”

My favorite part in the whole infographic: “electrons are electrons”

The EV pay-back IMPROVING at cold temps was an interesting observation. But the problem is that EVs often have very limited range as is such that when you lose some range during the winter, you may become at risk of not having enough range to satisfy your daily driving needs.

Workplace and shopping place charging would probably help a lot in cold places. Even if you don’t get much battery charge from them, just being able pre-heat your car from AC power could be very helpful.

That’s why we have a decade of EREVs like the Chevy Volt that just lets the extender dismiss any road or weather calculations.

It is interesting to see these things set out nicely in an info graphic but I have a few comments 1. Why does an EV’s range change with air density? if it is to do with drag then air density will have the opposite effect in an EV to an ICE. At altitude an EV will have greater range and an ICE will have less range. 2. The heating values are a bit miss-leading as an ICE produces way more heat from the engine than useful work so all that you are seeing in the changes of the mileage is the fact that the heat is becoming more useful. It would have been nice to see the hot weather figures as the ICE needs to dump more heat than the EV. 3. Anything that the car has to do that is extra to moving forward will have a greater effect on range in an EV compared to an ICE because an EV is about 4 times more efficient so even small changes (like turning on the AC or going up hill) can have a much bigger % effect on mileage. It would have been nice to show a direct comparison… Read more »

‘ Why does an EV’s range change with air density? if it is to do with drag then air density will have the opposite effect in an EV to an ICE’

That is a non-sequitur.
Drag is drag for both, and increasing air density decreases range for both.
The effect is less in the ICE as at any given speed less of the work of the engine goes to overcoming drag, with most of the ICE cars losses elsewhere.

Due to lowered air density both get more range at altitude due to lowered drag.
The effect is masked in the ICE due to the much greater drop in efficiency caused by inefficient combustion in lower oxygen.

The main reason an ev does better at altitude, in the mountains for instance, has very little to do with air density and more to do with less oxygen at higher altitudes, so the air is thinner and combustion is less efficient. I am no expert but the drag coefficient difference would have little effect and would be exactly the same for both types of vehicles if they were the same body style. You could say that since all ev’s by design can be more efficient due to not having air passing over a radiator for instance, that their innate drag is less in general, but that differential would be relatively the same at different altitudes..

At 10,000 ft (3000 m) air is only 70% of density of sea level, so drag is less. But as @ffbj states areo dynamic effects are same for EV & ICE (for the same body style). Howerver for ICE power drops off due to less air; to maintain same performance, more (less efficient) power is needed. EV motors have constant power performance regardless of attitude.

If a vehicle is driving in mountains, the efficiency differences multiply. 1) Going up steep hills requires more torque, thus for ICE a less efficent higher RPM (with a lower gear ratio). Torque for an EV motor is relatively constant, so there’s little change in effiency. 2) Coming down steep grades, an ICE will need to use breaks (wasting energy as heat), or use over-drive gearing ie: compression and friction of the engine (released as heat) with to maintain a safe speed. Going downhill, an EV can regen energy instead of using breaks to capture and store the excess energy in the battery pack.

note: EV regen efficiency can vary depending on the batteries SOC (State of Charge) and battery temperature (depending on pack design).

I assume that the figure in the graphic is a combined figure.

As the air density goes down the drag goes down which will help both cars but the ICE engine would suffer because it needs O2 which will reduce with a drop in air density. I know driving at altitude reduces the ICE MPG with a 5% reduction seeming pretty reasonable. I can’t work out why a change in air density would reduce (or dramatically increase for that matter) an EV’s range. All an EV needs the air for is to cool the battery and to keep the pink thing behind the wheel alive so why would it loose 6% range?

Two items that are odd with this infographic … as in the efficiency values should be similar for both ICE and electric vehicles.

1. Tires (winter & inflation): -13% EV vs -4% ICE (should be no difference)
2. Air Density: -6% EV vs -5% ICE

Did you notice that difference between summer and winter driving costs for ICE is 3.6¢ per mile which greater that the year-round average total cost for opperating an EV at 3.3¢-3.4¢ per mile?
– ICE:18.6¢ winter vs 15.0¢ summer
– EV: 3.4¢ average (3.8¢ winter vs. 2.6¢)
ie: An EV can be driven on just the difference between ICE costs of summer vs winter efficiency.

Nice info.
Unfortunately the issue for BEVs in cold weather is not how much they cost to run, but reduced range.
They are not cheap if they don’t get you where you need to go.

That is really the main understanding for a person buying a new BEV . There should be a temperature-to-miles graph provided by every manufacturer. They should also be informed to pad an additional 20 percent for battery degradation over the life of the vehicle.

HOWEVER, it would then help to provide an information graph like the one provided here by Fleetcarma.

Although EREVs really are not hurt by this cold weather anxiety, they too strive to drive all electric more than other PHEVs. That is why the 2015 Volt will most likely have 50 AER. 150-200 mile BEVs are going to cure a lot of this as well.
http://insideevs.com/can-evs-handle-cold-weather/