Video: BMW i3 REx Range Test


In this video, Road Record’s Maggie Barry takes the BMW i3 REx for a range test around Scotland.

BMW i3 REx Range Test - No Recharging - No Refueling

BMW i3 REx Range Test – No Recharging – No Refueling

The idea is that she’ll drive it continuously without recharging or refueling to see how far the i3 REx can travel.

The end result is unclear or at least imprecise, but Barry seems to be implying that through knowledgeable use (knowing when to turn it on, which is not driver selectable in the US) of the REx and range-saving driving techniques, 170 miles of continuous driving range is possible in the i3 REx.

After those 170 miles, you’ll either have to recharge, refuel or both.


Categories: BMW, Videos


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28 Comments on "Video: BMW i3 REx Range Test"

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She makes some good observations , but as noted its not a helpful review in terms of determing range. REx has been ruined in the USA for no good reason.
Driver should have the option of controlling rex cut in point.

Why is the US version different? And when does the US version switch over to Rex? 10%?

The ranger extender just makes so much sense. More cars need to incorporate this. You basically eliminate the short comings of the battery in a simple, effective mechanism. with the REx, this car has the same range as a 60kwh Model S but for 1/2 the price. And as we all know, it’s a rare day when we use 170 miles of driving.

Actually Model S/60 is EPA rated at 210 miles which compares to 80 miles +limp home mode for i3 REx. Also i3 REx is just 36% cheaper than Model S/60 rather than “1/2 the price”.

Range of i3 with REx is 180 miles, range of 60kwh Model S is 208 miles. So same neighborhood.

MSRP of REx is $45k before incentives. MSRP of 60kwh is $70k before incentives. So significant price difference and that’s before “options” (which let’s be honest Tesla takes some liberty in pricing here in order to make the base price seem more manageable). A fully optioned i3 (all the bells & whistles) is $47.5k post-incentives, a fully optioned Model S 60kwh is $88.5k which is
-46% cheaper. Okay not 50%, so I rounded up… btw note all the features the BMW i3 has (autonomous parking, etc) that Tesla doesn’t – the car is much more of a luxury interior.

Plus a REx isn’t an ICE, it’s a generator and you’ll rarely use it. Maintenance will be rare as its a very simple engine.

It’s masterful engineering by BMW. The car is BMW quality and elegant for close to -50% cheaper than a Tesla but with similar range.

Both cars are great. Both are engineering marvels.

Both should help steer consumers – including the cool-car-fanatics among them – towards EVs, using less oil, and hopefully break the back of Big Oil’s climate-change denial machine.

Next, please 🙂

The way I see it i3 is a very expensive and rather oddly styled city car with limp home *ICE*range extender for those who ventured too far out of the city. Model S is more of a high performance full sized car designed for long distance travel and supported by Superchargers to that end.

Different cars for different purposes that aren’t really competitors. Of course i3 is cheaper than model S for the same reason you pay less for a one series than for a seven series.

I like my electric car oil-free, thank you. I’ll deal with reduced range to avoid maintenance on an ICE.

Exactly! And “dealing with” is such a smaller inconvenience than I had ever imagined. I had to go to the petrol station last weekend to fuel my utility vehicle, and it was so cold outside (and smelly and dirty). It was a bigger inconvenience than any thought I give to running the EV on every other day. I realized I hadn’t been to a petrol station in weeks, and will be very happy to continue avoiding it as much as possible! People talk about the EV being a good second car, but in my life it’s the main car and the gasser is just for hauling and long runs, and almost not worth keeping. If only renting something that you can muddy up and leave equipment and toolboxes or bikes in for part of the year was easier.

I agree as I own a Leaf. However I wonder what the maintenance is on a generator vs an ICE? I imagine it’s much simpler with extended intervals due to minimal use. Seeing my range reduced by nearly 50% during Chicago’s artic winter, I wouldn’t mind some ICE insurance.

How about a write-up of the maintenance required on a volt/i3?

Had a 2011 Volt for a 3 year lease and now into a 2014 Volt on lease. Only service on the 2011 Volt was a single oil change at about 18,000 miles and tire rotation.

I have about 30K miles on my Volt in about 21 month.

Only about 180 gallons of gas used. I have changed oil only once so far (Free offer by the dealer). And I have done 2 tire rotations (which is NO different whether it is electric or ICE).

So, the Volt requires very little services…

I agree. I wish our Leaf had a range extender. We also have a Volt and we drive as an EV 98% of the time. With the BMW’s higher EV range it would probably be like 99.5% of the time. I’d still pay the extra for the Rex, though. Just because it would be nice piece of mind and could make longer trips out of town if necessary. Since the Rex won’t get used much, I doubt it will have much of any maintenance to worry about.

It’s already speculated that Nissan will come out with a 135 mile Leaf this year at a $5K premium that would still make it $10K cheaper than i3REx. Would that work for you?

I think if the Leaf had a 130 mile EPA range and there were plenty of quick charge stations to allow me to get from Ft.Worth to Austin, Houston, San Antonio, and Abilene.. I’d call that good enough. That would make the Leaf capable of regional trips. Usually anything further than that I’d take a plane anyway.

Truth be told.. if there were enough quick charge stations, we could do that NOW with our Leaf, but we’d be stopping twice as often for a charge.

Sorry, I wasn’t too impressed with this video. I didn’t learn anything I didn’t already know and I don’t think a laymen watching this would grasp what the Rex is and how it works.

I have read somewhere its 5% the cut in for the rex in the usa
hard to believe its that low.

Probably 5% of the the given allowable DOD, which may leave another 10+% that doesn’t show on the dash.

If the i3 delivers 65-70 EPA AER, on 22kwh, it would still be a big jump in per/kwh numbers, over say the Chevy Volt’s 2.3 miles per kwh EPA number (38/16.5). This is another way of highlighting the Volt’s shallow, 65% allowable DOD. It’s also a story of what shedding 1,000 pounds can do.

Over 27,000 miles on a 2011 Volt and now another 2500 miles on the replacement 2014 Volt, we are consistently getting 40-45 miles AER, which comes out to almost 4 miles/kW. Of course we live in the Sacramento area with mild winter weather and rather flat terrain.

Your Volt energy efficiency computation is confused as the Volt only USES 10.5-8 kW of that 16.5 kWh battery pack.

“over say the Chevy Volt’s 2.3 miles per kwh EPA number (38/16.5). ”

Where did you get this wrong information from?

1. EPA never gave that rating. Volt’s EPA rating is about 98MPGe which translates into 2.9miles per KWh. That EPA rating includes the 15% charging loss. So, if it is range efficiency, it is more like 3.33 miles/KWh.

2. Volt only allows about 10.5KWh usage for every 38 miles. So, in that sense, it is 3.62 miles/KWh.

3. Volt has lower Cd than the i3 with REx and it also has less aero drag due to the total FA x Cd. However, Volt is heavier and has far more tire resistance than the i3.

4. The projected i3 REx MPG in REx mode is worse than the Volt due to the tank size and about 80 miles range. 80/2.4 = 33.33 mpg.

I found out that the local car dealers in my area are going to have a party for this car when it officially goes on sale April 29 in Central with a party and a test drive. I think I will try and go to take some pictures of it.

We know that the i3 with Rex, has not been driven/reviewed in a car certified for sale in the US. When it is possible to hear it, and experience it’s limitations, the desire to own one will be modified by Reality.
In fact, the “early adopters” who have placed orders, may have second thoughts when their cars arrive in May and they discover how little they are getting for their extra $4,000.

I think the state of charge is 6% when the engine kicks in, for the states. Since it’s not classified as an electric car in the states, they should raise the state of charge so there is no performance loss on long inclines. 6% buffer is nothing.


The little range-extender seems to do its job well .. . I just wish it wasn’t $4000 extra. That seems a bit steep for adding a 2-cylinder ICE.

I like the REx idea very much. I am NOT sure I am completely on board with BMW’s execution.

1. The REx should be allowed to come on with 50% charges left for mountain driving.

2. The REx heat should NOT be wasted when this $4K option is selected.

3. A slightly more powerful engine should be equipped for full loading and long distance travel.

Of course, none of that are issues since BMW designated the car for “city only” and REx is only used for occasion to get you home.

I wonder if the next version of the Volt with a smaller 3 cyclinder engine would do a better job at this.

I think a 60 miles EV range with a small gas engine (around 1L and 50 HP) for extended driving is ideal.

Looks like many i3 are ordered with NO Combo plug.

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