If I’m not mistaken, the much more important element is air resistance. The power-efficiency ratio of electric motors is nearly constant, meaning the energy usage per unit distance is nearly the same at all speeds, but there is more air resistance at high speeds.
Comment on Tesla Cybertruck gets less than 80% of advertised range in YouTuber’s test
andrew_bidlaw@sh.itjust.works 5 months agoHmm. So it’s a sneaky little argument for EVs for an in-city use? I wonder why no company screamed about it through a loudspeaker. If that’s so, it’s a killer feature for most drivers
QuaternionsRock@lemmy.world 5 months ago
psycho_driver@lemmy.world 5 months ago
You are correct. Electric motors are 100% efficient, so a combination of air resistance at speed as well as more regenerative braking being done during city driving are the reasons for better city driving effective mpg.
WhiskyTangoFoxtrot@lemmy.world 5 months ago
Electric motors are 100% efficient
Umm what? Have you never heard of the laws of thermodynamics? I mean, the overall thrust of your argument is correct, but that statement is just nonsense.
Oh, and using regenerative brakes will always waste more energy than not using brakes at all and simply moving at a constant speed. Regenerative brakes are only efficient compared to conventional brakes, which waste all of their energy as heat. Braking more in the city driving doesn’t improve an EV’s efficiency there compared to using that same EV on a highway (aside from the fact that you’re driving more slowly overall,) it just improves its relative efficiency compared to ICE vehicles with conventional brakes.
andrew_bidlaw@sh.itjust.works 5 months ago
That’s the same for a fuel-based cars. Some other users told me about the black magick trickery electric cars do in the city. Guess you’d like to check their replies too.
psycho_driver@lemmy.world 5 months ago
Gasoline powered engines are very inefficient in terms of getting all of the potential energy out of it’s fuel source. They do have a sweet spot, usually somewhere between 2,000 and 3,500 rpm and most companies will tune their vehicles to be at highway speeds while in that sweet spot. The rpm range from idle (ICEs needing to idle at stoplights decrease city MPG) up to that sweet spot is less fuel efficient than rolling around in the sweet spot, so a lot of stop and go driving will see a gas motor running out of it’s fuel efficient range quit a bit.
Electric motors have the same efficiency at any rpm and they don’t use energy while the car is sitting still.
hperrin@lemmy.world 5 months ago
It was one of the main selling points of the Prius. Great gas mileage, especially in city driving.
SoleInvictus@lemmy.world 5 months ago
This is correct. I’m a Prius driver. I get 45-55 mpg on the highway, depending on conditions. If it’s just city driving, I get 55-65 mpg. I’ve had as high as 72 mpg, many years ago driving Uber downtown.
abhibeckert@lemmy.world 5 months ago
Not to mention with a short commute and a plugin model Prius… you won’t use the ICE power unit at all.
SoleInvictus@lemmy.world 5 months ago
Man, don’t I know it. The 2023 Prime is out with a 39-44 mile range, which would cover about half my total daily commute, plus my employer has free charging. Someday…
andrew_bidlaw@sh.itjust.works 5 months ago
Not being a car guy, I missed it all.
Thanks, I’d keep that in mind.