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Old 05-17-2020, 08:51 PM   #112 (permalink)
Master EcoModder
Join Date: Dec 2008
Location: Eugene, OR, USA
Posts: 339

Lord Vader - '15 BMW i3 REx
90 day: 35.06 mpg (US)
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Next step: Wheel width and offset comparison testing.

So as somebody who likes to race my car when I am not geeking out on efficiency, I have been very interested in the real world impact of using wider wheels and tires on my car - and I am hoping to improve front end traction, but that part really doesn't matter here.

The stock setup for mine is staggered 5.0" and 5.5" wheels with 155mm and 175mm section width tires as standard. Non-range extended BEV models get the narrower wheels and tires on all four axles. The BEVs also have an officially advertised Cd of 0.01 lower. So with that said, I have purchase a complete set of staggered wheels in the same style as mine to see if I can actually measure a difference in aerodynamic performance between full skinny, staggered, and full wide setups. Eventually, the wider wheels will likely end up with 195mm section width tires on them which I will test as well.

My hope is that between throttle stop testing and new OBD data I have been able to acquire on reported motor torque from the Deep OBD app, I can make some real world conclusions about how much this really impacts things. Obviously, I don't think going wider in any respect is going to improve efficiency, but it would be nice if I can determine what impact it really has, right?
2015 BMW i3 REx
2011 Ford Flex SEL AWD
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