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by mortos 124 days ago
Weight has nearly no effect on range of an EV. The YouTube channel Aging Wheels has two good videos on this.

Here he talks about towing, and he demonstrates loading the truck to max capacity makes nearly no difference: https://youtu.be/UmKf8smvGsA

He also covered an attempted Cannonball run where they stuffed two extra battery packs into a Rivian R1T: https://youtu.be/yfgkh4Fgw98

Real differences makers are smaller wheels and aerodynamics
3 comments
nomel 124 days ago
> are smaller wheels

Looks like rolling resistance decreases with diameter [1]. So, is it from the increased drag from higher stance? Would lowering the car the same work better?

[1] https://www.tirereview.com/science-behind-rolling-resistance...

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mortos 123 days ago
I think it's mostly from aerodynamics. Lowering the car could help but even just smaller rims, with the same overall diameter (rim + tire), can have a 15% impact on range. This Engineering Explained[1] video does an okay job with some of the math but he clarifies it well with a comment:

> CLARIFICATION! Why do bigger wheels mean worse efficiency, when the overall tire diameter remains the same? This comes down to aerodynamics. A 20" wheel will cause more of a disruption in airflow than an 18" wheel. That's why Tesla (and others) uses aero covers on their wheels (Car & Driver testing showed it gives about a 3% efficiency bonus at speed). The smaller the wheel, the more of the side profile of the wheel & tire is perfectly flat (the tire is flat, the wheel open: more tire = more flat area, less open area). Ideally, you'd have just a plain, solid sheet for the wheel, but obviously that's not idea for brake cooling. Wheel covers are today's common compromise as they have some airflow, but minimal.

[1] https://youtu.be/NYvKxsYFqO8

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nomel 123 days ago
> solid sheet for the wheel, but obviously that's not idea for brake cooling

So, temperature driven radial louvers!? :D

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Animats 123 days ago
That's interesting. It demonstrates that regenerative braking really works. The energy you expend going uphill, you mostly get back going downhill. The energy you expend speeding up, you mostly get back slowing down. His tests were a round trip, so start and end altitude are the same. And he kept a fixed speed on a freeway, so there wasn't much acceleration energy expenditure or energy loss into friction brakes. You don't get drag or rolling resistance back, so that apparently dominates. Those don't vary too much with load.

Nice result.

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actionfromafar 123 days ago
It has an effect on the range of the tires.
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