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by Spooky23 1573 days ago
My dad was a rural mail carrier. It’s stop go stop go. I don’t think it would be a great EV use case at all.

USPS is pretty smart/efficient with this stuff.

5 comments

Low speed urban stop-go driving is where EVs excel versus ICE, I think?
It’s pretty extreme. Brake pads every 7-10k miles.

I would think that it would be pretty draining. Perhaps not!

EVs slow down by generating power and putting it back in the battery. Many EV owners report brakes lasting 100k miles or more due to the reduced usage.
Again, with regenerative braking, something else that EVs are also better at :)
Regen braking is extremely weak and takes a much longer distance than you'd imagine to bring the car to a complete stop. The best use-case for it is slowing from high speeds to moderate speeds, whereby the deceleration is greatest and the recharging is most powerful. For instance, imagine exiting an 80 mph highway onto a 40 mph access road. It's worth noting that the rate of deceleration on regen brakes decreases as the speed approaches zero, rather than the reverse as with non-thermally-overloaded friction brakes. Fundamentally, this occurs for the same reason that stopping a given car from 120 mph takes more than twice the distance compared to stopping the same car from 60 mph - part of the equation of calculating the kinetic energy (what's powering regen brakes) of a moving vehicle involves squaring the speed of the vehicle. With this in mind, braking duty cycle of a typical urban or suburban mail truck (which does a lot more 25-0 than 80-40), is pretty much the worst possible duty cycle for use alongside regen brakes - you are getting almost no energy back and almost no braking force in this specific duty cycle.
Have you driven an EV with “one-pedal-driving”?

I agree that the regen efficiency is reduced at lower speeds, but many EVs are perfectly capable of coming to a stop quickly on regen and only apply the friction brakes right at the end of the stop.

I have, I owned a Tesla Model S P85D for a while. Had to turn off one-pedal-driving. I found it substantially less intuitive than two pedals for any kind of spirited driving, which is what I do every time I get in I car I own. I've had 5 corvettes, 3 GT-R's, and currently driving an 800 hp Mercedes AMG GT S (2 door coupe, not that horrid 4-door atrocity), so I'm admittedly not the target demographic either for one-pedal-driving or EV's more broadly, as they currently stand.

My standards for what qualifies as "strong" braking are probably bordering on alien for most people, too - about 95 feet for 60 mph to 0. That Tesla took almost 120 feet. A new Honda Accord takes about 130 feet.

That's exactly the driving pattern EVs are most efficient at
stop/go/stop/go is perfect for regenerative braking at the very least(not necessarily limited to EVs, but more common with them than ICEs). Also, on the stop portions, there would be zero emissions. I imagine the stop portions are probably a bigger overall part of the day than the go portions, at least based on how my mailman operates.
Stop/go is perfect for EV, although I think rural areas are not a good choice.

Maybe they should do a mix: EV urban, and gas rural.

its great for EV, its low speed, they do best in stop and go type traffic.