BEV vs REX

In general I’d recommend going with a BEV (battery electric vehicle) unless you need the REX (range extender).  At the end of the day the BEV will be lighter, handle better, more efficient, and have less maintenance and fewer things to break.  You will need to get the REX serviced every 12 months (oil and filter change typically, but will require more as it gets older).  The BEV as a 24 month service interval.

It is important to understand that the REX is not a hybrid, rather a range extender.  In a hybrid vehicle, the engine and electric motor are connected to the wheels and can move the vehicle. The i3 ONLY uses the electric motor to move the car (for both BEV and REX versions).  The battery and motor in a hybrid is supplemental to the engine whereas the primary use case of the REX is to actually, not use it at all, and only at low SOC (state of charge) does the REX even turn on.  The REX will not run until the battery is almost dead (around 5% SOC).  The power output of the REX is not enough to power the car on the freeway either.  The out of the box experience of the REX in my opinion is not great in my opinion since by the time it kicks on, you’ll be forced to slow down due to the slow charging speed of the REX anyways, so you might as well stop and fast charge.  Fortunately, it is possible to enable what’s called “hold state of charge” for the REX.  This allows you to turn on the REX much sooner so that you can continue on the freeway (even if it is still discharging the battery) but you have lots of battery charge remaining so you won’t mind.  This allows you to get the full range of the REX and battery without having to slow down, or stop and wait for the REX to charge the car.

I do think if you’ll be frequently using the REX due to the large distances you frequently drive the i3 may not be the best car for you.  The MPG with the REX is good, but not great.  It’s likely better than most older ICE cars, but an efficient hybrid should have no trouble meeting or even exceeding the MPG that the REX would return, and then you’d never have to stop and charge.

A great reason for the REX however, is if you live in a CARB state.  With the REX, you are given a 10 year or 150k mile warranty (which ever comes first) (California may be 15 years/150k miles) for all emission’s related parts and batteries (would include troublesome AC compressors on earlier cars).  You’ll want to research Partial Zero Emissions Vehicle (PZEV) emissions warranty if this applies to you, but it may make getting the REX worth it.  The warranty does not apply to BEVs.