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0 pointseightysixfour2y ago0 comments

This is partially it, but it isn’t hard to calculate the CdA of a car and then add resistance to the rollers equivalent to the expected wind resistance, however the bigger reason is that cars operate in a dynamic environment and you don’t actually want to know how far they’d drive at 100kph with no additional wind in a straight line. It just isn’t helpful.

The driving cycles have a number of issues but they purposefully try and capture more of the range of dynamics to help consumers better understand what they should actually expect from vehicles.

It is like comparing CPUs only on their ability to multiply quickly vs a suite of software benchmarks.

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phtrivier2y ago

Thanks, I would not have suspected drag.

Still, it seems like you're saying "the number would be unrealistic", but I'm not sure people want a realistic number, just a "worst case scenario"...

I understand that standard tests try to measure something "realistic", but they end up giving a value that is not what people are waiting for - which is, again, and I can't stress it enough because it's 100% of the conversation i still have about EVs with every single person I talk to - "insurance that I will be able to visit my mum on a single charge at the other end of the country".

I understand it's a bad question to ask and people don't really need _that_ range, but apparently they need _that_ info :/

eightysixfourOP2y ago

Right, but those people would then get their EV, go for a 20km drive in bad EV conditions, see their range decrease by 30km, and call the manufacturer a liar. Been there, done that. Family member sold theirs because they weren’t “confident in the range” despite never driving more than 80km in a day.

Truth is I think some people just don’t want them and they look for a “logical” out since that conflicts with their desire to be less impactful to the environment.

A 75kwh battery pack has the same energy as ~8.5 liters of gasoline. While the conversion of that energy to movement is far more efficient than a gasoline engine, that’s still a small amount of energy comparatively, so the variance is going to be very, very high.

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