Tom on the i3s

Source: https://insideevs.com/2018-bmw-i3s-six-month-update/

BY TOM MOLOUGHNEY

Does the BMW i3 (Sport) still impress after living with it for a time?

After a little over three years with a 2014 BMW i3 REx, I picked up my 2018 BMW i3s BEV on December 30th, 2017. It was actually the very first i3s delivery in North America.
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Bob Wilson

If they do increase the battery to 42 kWh for the 2019 or 2020 models, I'll be kicking myself. A battery above 40 would be the point that I no longer need a REx, since I could get up to SF and back or down to Paso Robles without making any charging stops. As it stands now, I rarely need the REx, but it is a requirement for those scenarios.

I definitely agree with his points on the S's ride quality. It's not quite perfect, but I put it on par with my e-Golf as far as road noise, handling, and overall smoothness. It's a definitely improvement from the 2014 and 2016 models I had test driven.

I realize Tom's review is specific to the BEV, but think it's worth talking about the REx and what it does and doesn't do. I had an unpleasant surprise using it this weekend in after about 25 miles at 75 mph, I got the low power warning. The AC nearly shut off, which was horrible timing as it was over 100 degrees outside and there were no charging stops for 15 miles either way. Dropping speed down to 60 mph let the charge rebuild and restored normal power. We arrived at our destination a bit warmer than we'd like, but did make it.

Ever owned one of the old, VW bugs? Couldn't get out of their own way. While the electric motor is many multiples of those, driving at 75mph, it should not be surprising that the REx can't keep up the SOC, which will gradually slip away. Once you've exhausted the battery, you're driving with the REx's output. It tries to maximize your go power, so it starts to shut down some of the creature comforts. It was a design decision, but should not be a surprise. A larger battery would just let you charge along a bit longer before the same thing happened unless, or until, the REx gets larger, which isn't really needed on a car designed for short distance commuting in/out of the city.