BMW i3 REx With Battery Depleted: 0 To 60 MPH In 13.7 Seconds


BMW i3 With REx

BMW i3 With REx

BMW i3

BMW i3

In the Edmunds long-term test garage is a BMW i3 REx.

Recently, Edmunds put the i3 REx through its standard battery (pun intended) of tests, which includes acceleration, handling, braking, etc.

We’ll focus solely on acceleration here, as the test methods from Edmunds reveals figures we’ve not seen published before.

Test Results:

Acceleration: (All runs with Traction Control on. Secondary runs are with the battery depleted and range extender recharging the battery)
0-30 (sec): 3.1 (w/ battery depleted 3.8)
0-45 (sec): 4.7 (w/ battery depleted 7.7)
0-60 (sec): 7.1 (w/ battery depleted 13.7)
0-60 with 1-ft Rollout (sec): 6.8 (w/ battery depleted 13.3)
0-75 (sec): 11.2 (w/ battery depleted no time)
1/4-Mile (sec @ mph): 15.6 @ 85.6 (w/ battery depleted 19.2 @ 64.7)

It’s clear from these test results that the i3 REx is not peppy (0 to 60 MPH in 13.7 seconds is Geo Metro territory) when its battery is depleted.  Additionally, the i3 REx was not capable of reaching 75 MPH in battery depleted operation.

Source: Edmunds

Categories: BMW

Tags: , ,

Leave a Reply

53 Comments on "BMW i3 REx With Battery Depleted: 0 To 60 MPH In 13.7 Seconds"

newest oldest most voted

So, with the battery depleted you need to drive sensibly, and avoid interstates. Good advice anytime.

Unless you’re already on the interstate. Then what?

More battery needed.

No, simply don’t drive with the battery depleated. You could also charge the car in stead of running it empty and then driving like a mad man (or at leat attempting to)


So… I’m guessing when they use the term “battery depleted” they probably mean that there is no buffer at all left in the battery. Because if there was still the buffer then it should perform just as normal.

Buffer is 6% (where the REX starts), the limitation is meet if you go under 2%. To go under 2%, you have to push the car for an extended period of time (over 70mph, steep incline).

Disclaimer: I own a BMW i3 REX I’m not going to contest the number, they are what they are. But ask me how many time times I used the REX in the last 2 months (in one of the most figide winter seen in recent years)? Answer: Once, for a big 5 minutes. Why buy the REX if I don’t use it? For freedom and peace of mind. No need to plan, I just drive my one and only car. Because I can go even further if I choose to. When I do, I understand I will need to be aware of how heavy I press on the accelerator and the response won’t be the same. But I’m not stuck, I don’t have to plan, I don’t have to rent an ICE. I hear the comment, yeah but it’s limited and you can’t drive over 70mph without getting into “limp mode”. During the holidays, I drove over 650Km on the REX, I kept my speed under 70mph and NEVER got into “limp mode”. I was still able to overtake cars (and going over 70mph for a short periode of time). No problems on hills either. But I don’t live in… Read more »

While I understand your reasoning, I find it somewhat frustrating (from a macro perspective) that BMW gets a pass on what would be loudly trumpeted as a disqualifying failure on, say, the Volt.

GM did an outstanding job in making sure the Volt has consistent performance on or off gas. Must be nice to be able to sell a car with utterly unacceptable performance, as long as you slap the blue-and-white roundel on it.

Dan, the Big 3 built cra*** cars for decades and they now are widely hated by people who have either been burned by them or are brainwashed into looking down on anything made in America by American firms.

I love my Volt, but I have to admit that GM can be remarkably obtuse at times. Nissan, Toyota and BMW may be wrong from time to time but they have more fanboys and get the benefit of the doubt, even when they don’t deserve it.

BMW is getting a pass? Not here for sure.

Hit the search button with i3 REX and you will find a larger share of post focusing on the REX. It’s not perfect, but it’s not bad either.

I can be perceived as a fan boy, may be I am, but I try to balance my post and provided a point of view of an actual owner.

Spider-Dan, I totally agree with you. I couldn’t say it better.

I disagree, the Volt and i3 are different vehicles with different purposes.
I consider the Volt a true plug in hybrid, suitable for long distance travel with no charging available while still providing the benefits of electric power for normal trips when charging is available.
The i3 is a range extended electric vehicle. The range extender is not intended to provide the full power experience, but rather provide you an option for the rare times you need to go beyond the batteries capabilities. If this will not be a rare thing, then the i3 is not a wise choice. Providing a full power experience would cost more and incur a significant weight penalty. I think they made the right choice for something that should be rarely used.
Get the vehicle that meets your needs. If you need to haul manure, roll coal, and talk smack; there are better options than the Volt or i3.

Sorry bit i doubt that providing the i3 with an adequate engine better than the Chinese built, Korean company Kymco supplied current 650cc engine will raise the i3 price over the current $50,000 average selling price.

The i3 REx is a pure series hybrid- we really should commend BMW for staying pure. There will be limitations when compared to other plugin hybrids, like the Volt. As much as we want to pretend the Volt is a series hybrid, it isn’t. So I don’t think it’s fair to compare the two so closely.

GM made a decision to abandon the pure series hybrid concept in favor of an electrically dominant series-parallel hybrid. They made that decision because of the exact same limitations that the i3 REx is experiencing.

The i3 REx is an awesome car. If the prices were equal and even if the i3 REx wore a Chevy bow tie, I would choose the i3 REx over the Volt. Both are amazing cars, but the i3 REx fits my life better than a Volt would.

There is nothing more ‘pure’ about an i3 Rex than a Volt other than its longer EV range. Once the gas burning kicks in, both are in similar boats — although, yes…. the Volt’s ICE on occasion can be clutched into helping drive the wheels when its electronics determine more efficiency is gained by doing so. That the i3 cannot do this by no means justifies implying it is superior to the Volt due to it being (falsely) ‘pure’.

I advocate for EV’s in my local area.

Sorry, but I just cannot find a good reason to push for the BMW i3 REX.

For most people, I’d recommend the Nissan Leaf. If range is an issue, then I’d recommend the Chevy Volt. If tech is important, then I recommend the i3. I can’t find good reasons why the layperson would want a poor REX implementation.

I’d say go for the i3 REX over the Volt only if you are like franky_b and want a longer AEM EV, want the piece of mind a REX provides that you will seldom use, want the latest tech and don’t mind paying nearly double and don’t need as much cargo space as the Volt and don’t mind that AEM range cannot be refilled by CHAdeMO.

I have tested all the above vehicles.

Double? The Volt with the same options (or close to) as the i3 retail at close to 42K$CAN, my i3, 55K$CAN. The Volt and the i3 are both great car. It’s not one versus the other, it’s which one better fit your need.

At the end EV Range, yes, the tech and interior finishes tip the scale for me.

And in my region, DCFC support both CHadeMO and Combo.

In New Zealand
BMW i3 Rex nz$75,000
Volt nz$85,000
Nissan Leaf nz$40,000
Outlander PHEV nz$60,000
Tesla S N/A
No Government rebates of tax credits.

You can get a new base i3 REx where I live for $41,000 before tax credits.

The i3 REx is a pure series hybrid. As much as we want to pretend the Volt is also a series hybrid, it is not. That makes the two difficult to compare directly since their intended use is different. There’s also the issue of branding. BMW is a premium brand.

The i3 REx definitely fills my specific needs more than a Volt, but even with the $41,000 pricetag, it’s still outside of my budget.

Once their gas engines kick on, how is the i3 purer than a Volt? Are you saying BMW burns oil more purely than the Volt does?

what he means is that the BMW i3 ReX is more “pure” because the gasoline engine never engages the drive train whereas in the Volt, the gasoline engine can engage the drive train.

this distinction of EV “purity” based on whether the ICE “turns the wheels” is a crazy notion that is only of interest to EV enthusiasts. the BMW approach is much less efficient, which goes a long way in explaining why the i3 ReX is much lighter than the Volt but gets fuel economy that is no better than that of the Gen1 Volt.

Well said. Another issue with the BMW i3 REx is that the “sin” of burning oil is NOT fully redeemed by recycling the heat of the engine where the Volt does in the winter.

So, the so called “purity” of series-parallel is just another crap made up by BEV purists…

Both i3 REx and Volt are awesome car and they give us choices.

I would love the i3 REx more if it offers a real rear doors, better heat recovery from the engine AND SW to enable you to turn on the REx early.

I would love the Volt more if it allows DCFC and gets a performance upgrade.

Good to hear some real time experience!

Thank you for your post.. I have more or less the same reasoning. And here’s the thing I just absolutely don’t understand about the Rex haters out there.

Take the regular old i3 BEV. I don’t hear any complaints about it. It has about the same range as a Leaf. But then you take the i3 Rex, it can do everything the regular i3 can do (for the most part) and MORE. It is infinitely more versatile with the Rex capability. So how could it possibly be a worse car?

And here’s my deal. I’ve been thinking about getting an i3. But I can’t possibly justify the BEV version because it does not have fast charging that is compatible with any of the stations in my area. So right now a Leaf actually wins out over an i3 BEV. But the i3 Rex would be an acceptable compromise. Just like you, I’d probably only use the Rex once per year. But when you need it, you need it.

I’ve been thinking about the i3 REx also. But with the looming 200 mile BEVs coming in two years, I’m hesitant to do so. Plus, i3 version 2 (not to mention i5 or other variants) should be a huge improvement.

The performance in range extended mode doesn’t stop me from buying the car.

It is frustrating that spending the extra to get the REx capability would make me lose AER and performance (even with a full battery).

And in Georgia you would also lose the states $5000 tax credit since it’s only available to pure EV’s, the REX wouldn’t qualify.

i think that your view of the Volt as being a “transition” vehicle is incorrect: the Volt is a mainstream EV. BEVs are primarily for EV enthusiasts, the problem with even 200 mile range BEVs (it is worth noting that actual range can vary widely due to conditions) is recharge time: even if you go to a fast charge station, 30-60 minutes of recharge time is still a lot in comparison to the 5 minutes for a gasoline refill. relatively long battery recharge times is what gives incentive to fuel cell technology, not crazy conspiracy theories about how FCV is a “plot” to undermine BEVs.

I completely agree.

The catalyst behind the development of FCVs is the fact that there is no charging solution on the foreseeable horizon that approaches ICE refueling speed. It is not a plot by Big Oil to eliminate BEVs.


Congratulations, it looks like you made a good buying decision in buying a car which fits your personal needs well, at least in the matter of EV range.

The problem is going to be with those who buy the BMW i3 Rex thinking it’s going to work as well in “range extended” mode as the Volt… which it isn’t designed to, and won’t.

Frank I agrree. I too own the i3 REX, since May 2014. I have used the range extender only 3 times, that was during the winter. Summer I was able to drive 91 miles with a passenger in the car with me. When I got home I had 11 miles remaing. I follow the speed limit and opt not to use ac or heat.

Yes I agree with others the real time performance has been informative.

As long as the car can eventually get to 65 mph, thats good enough for me.

My problem with the REX is its inefficiency in the winter time – no there’s a test that needs to be done.

What is the zero-60 with the electric heater on HIGH?

Can it get even to 40 miles per hour with the heater on? I would serious doubt it.

Keep in BMW had to hobble the REX in order for it to get ZEV credits from CARB for the model. In Europe, the driver can select when the engine turns on, as soon as at 70% to 80% SOC. So when you know you are going beyond the EV range, you can turn the engine on while leaving a large battery buffer, so you will very rarely be driving with the battery depleted.

BMW did not “have to” hobble the Rex version of the i3 to get carbon credits. BMW -chose- to lobby CARB to get a new “BEVx” category created especially for them, and BMW -chose- to hobble the range extender functionality so they could get more carbon credits than the car deserves.


I personally love the look of the i3 and as someone who thinks EV’s are the way of the future I welcome BMW’s entry into the market. That having been said, I personally don’t think the performance and price point for the i3 can truly be justified. There are a reasonable number of EV/EREV/PHEV alternatives with better performance and at better prices. The high price I might be able to justify as part of the luster of their brand. But, I’m surprised that the “ultimate driving machine” company would produce a car with such weak performance numbers.

Still, we have the BMW i3 and the market will be the final judge of whether it can survive against the Volt, Leaf, Fiat 500e, and any number of similarly marketed cars.

It is a BMW. You are paying for the badge.

I have see them selling i3s at the local dealership for 2500 down, $200/month for a 2year lease on a $49,900 i3. Its a better deal than many of the cheaper EVs out there.

When you say performances don’t justify the i3. Which performances are you talking about?

0-30mph? 0-60mph? The i3 isn’t the fastest, but no slump @ 7sec. If need faster, I guess you must be in a hurry to go somewhere often. j/k 🙂

Or is it the efficiency, because it’s been rated the most efficient EV.

What performances are you referring to?

I’m fine with that performance. I just think that the 2-cylinder Rex should cost no more than $2K extra.

The Volt is a second faster 0-60 in Sport Mode using the gas generator.

i3 just doesn’t make sense over a Volt

I’m sorry, but I just can’t miss the sarcasm with your handle being EVer and the fact your saying need GAS/ICE to be faster then i3.

It does for those of us who want a light, compact car with good interior space, who value rust-free construction, who don’t need REx functionality, and who want to drive the most efficient EV made. The Volt is just too heavy and too long for my tastes.

The i3 has been clocked at 0-60 in the 6.6-7.1 second range, depending if you go with the BEV or the REX. The Volt doesn’t come close to that. As an emergency backup generator that only puts out approx 25K watts compared to a drive motor that can draw up to 100kw or so, of course the perfomance will only be about 25% while driving purely off of the Rex.

The i3 certainly makes sense for those who want to drive farther than ~38 miles without burning any gasoline.

The only people for whom the i3 doesn’t make sense is those who regularly drive farther than ~81 miles (or a somewhat shorter range in truly cold conditions) and expect the i3’s crippled range extender to provide the same performance as the electric drive.

The i3 was engineered to be a BEV, not a PHEV. Expecting it to perform like a car designed, like the Volt 2.0, to work as well as either a BEV or a gas guzzler, shows either a lack of understanding or else deliberately choosing to ignore reality.

Again, IMHO too much emphasis on taking a single metric (0-60 time) and defining the whole car and any potential similar class / size competitive make. Why all the 0-60 at W/Open throttle fuss?

On my commute there is not even a place where the speed limit is above 45 mph and at that with surrounding traffic 0-60 bursts at full throttle are not able to be done “or needed” on a daily basis.

Seems a bit too narrow of a focus to define a vehicles overall utility as a make or break deal. But I guess if that is your “Alamo” then too bad. you might overlook an otherwise very competent vehicle over a few extra seconds to get to 60 mph.

maybe the RX should be called ERX – Emergency range extender. No right minded bimmer owner would ever accept 13.7 seconds to 60 in any normal driving situation other than in an emergency..Drivers car?? not in the ex mode.

I’m impressesd! The i3 is quite fast in the quarter mile! My Mini E only managed a 15.9 seconds in the 1/4. My souped up Geo Metro convertible(when it was gas powered) did consistent 20.1 sec at 65 mph and didnt feel slow. So i wouldnt say the i3 with the rex is slow or dangerous. Contrary to what everyone thinks, you dont need to drive 85 mph everywhere. My Geo did 93 mph flat out but i rarely drove it over 65. In my state, the highest speed limit is only 65mph and you will most likely find me zipping along at 57 mph in my Nissan Leaf. Even if im driving my Corvette, im still not exceeding the speed limit. Are they more forgiving of speeding violations in other states? Here in South Jersey i lost my license 3 times for speeding violations. So im happy to zip along at the speed limit in my EV in the slow lane now.

Each state is definitely different, we have roads with 85 mph speed limits in Texas. Diving at 65 is boarderline dangerous on some highways, driving at 55 would cause an accident.

I test drove the i3 and it has slightly stronger acceleration than my Leaf. The thing that annoyed me was the regenerative braking was ridiculously strong. I’m assuming that there’s a menu option in the settings that can lessen the deceleration caused by the regen. As it was it felt like I was driving with someone who has their foot one second on the gas and the next hard on the brake, and had to press on one pedal or the other constantly. With my Leaf I like the 3 settings that can be quickly adjusted on the fly. If I need to punch it to merge I just pull back on the drive selector real quick and then hit it again after I’ve merged. If I need a range extender though I’ll have to buy a portable generator, LOL.

Car and Driver’s test shows perhaps a more typical rex experience, where the car is running on the rex, but there is still the normal battery reserve:

Zero to 60 mph: 7.0/7.9 sec
Zero to 100 mph: 18.1/ N/A sec
Rolling start, 5-60 mph: 7.0/7.9 sec
Top gear, 30-50 mph: 2.6/3.0 sec
Top gear, 50-70 mph: 4.4/5.1 sec
Standing ¼-mile: 15.8 sec @ 86 mph/16.4 sec @ 81 mph
Top speed (redline limited): 92 mph
Braking, 70-0 mph: 160 ft
Roadholding, 300-ft-dia skidpad*: 0.80 g

we sure have an abundance of Passionate naysayers here – wrong, but passionate. Most agree that there is simply No single EV that can serve every user, but many go on to say that: Volt is WRONG because: i3x is WRONG because: Tesla is so completely WRONG because: Leaf is WRONG because: Humbly suggest that you examine what is WRONG with your particular hated cars, back off of the ‘definitives’ because most are WRONG (CARB urban myths are legion, check your facts) and most of All, realize that you hate the particular car Because YOU hate the particular car, Not because it is Bad for everyone or WRONG in some way. The big three of WRONGNESS do Not, under Any circumstances, Need or Require you to repeat endlessly your precepts about them. They are what they are and thankfully they all beat hell out of every monster truck, end of story. I owe a beer to everyone here that deduces that spouting defaming information -correct, nearly correct, or outright Lies- does not help the EV ’cause’ in any way, shape or form. If you have not yet gathered that the readers here are pretty cross-reference well-informed, you should read More… Read more »