this post was submitted on 03 Feb 2024
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I'm not sure if that's the most efficient use of resources. EVs can only be gearless if they have over a half-ton of batteries providing huge amounts of power to their electric motors.
PHEVs, such as Prius Prime, Volvo or other cars (US Market, sorry I don't know UK market too well), do have an EV-only mode. But the smaller batteries force them to use CVT or other automatic transmissions so that their torque/horsepower bands can be better matched.
I'm not convinced that having all of our cars filled with half-ton to 1-ton batteries is the best design.
I’m going to knock your socks off… The vast majority of “normal” EVs don’t have gears as such. There are one or two supercar EVs that have a high and low gear but that’s it. Many hybrids don’t have gears either. My Accord Hybrid has an “eCVT” which is just marketing bullshit for covering up the fact that it’s functionally an EV with a gasoline powered generator. Honda has programmed the ECU to do fake shifts to make boomers feel more comfortable with the new technology. It’s only imitating an automatic transmission with software trickery. The gas engine isn’t even mechanically connected to the wheels for like 95% of the driving I do. IIRC that tech was borrowed or heavily influenced by the Prius.
https://www.youtube.com/watch?v=jofycaXByTc
I've decided to do some research on eCVT. I was surprised at its actual implementation. Toyota Prius, Ford Escape, and probably Honda Accord does this.
Its basically planetary gear magic. A computer can control two or three inputs, while the outputs are hooked up to the wheels of the car. By changing the speed of the variable input (likely the electronic engine)... the effective gear ratio of the "constant" input (likely the ICE engine) is modified. In the most extreme case, the variable input runs backwards to have the "overdrive" gear ratio.
It seems like the Honda Accord is a planetary gear eCVT system. Planetary gears are always so cool, I didn't realize that a CVT could be implemented with one (albeit with a hybrid vehicle where you have 2 or more powered inputs).
EDIT: it appears that you are correct. Honda's Hybrid system is different than what I'm familiar with (which is what the above video demonstrated).
https://youtu.be/QLUIExAnNcE?si=7JzkfL8GfUUoFnbK
So you're right with regards to Honda Accord Hybrid. Very interesting. Its always surprising to me how different car companies are with their implementations.
I’m so glad you found that video! I’ve seen it before and was having trouble finding it again to post a link here. Since you’ve already fallen down this rabbit hole, might I suggest you watch some reviews of the new 11th gen Accord. Honda is not only adding fake shift points to an eCVT that does NOT HAVE FIXED GEAR RATIOS but they are matching those fake shifts with fake engine noises piped through the speakers inside the cabin. They’ve also regressed from the elegant push button gear selector in my 10th gen to a completely unnecessary shift knob protruding from the console in the 11th gen. It’s actually embarrassing how much they’ve had to dumb the car down for people who are either stuck in the past or people who are weekend race car drivers. Mercifully, most of this garbage fakery is only really noticeable if you really flog it or put the car in “Sport” mode.