[sirozha]

Yes, if you're using B mode at higher speeds, you've got to have a very steady foot, otherwise it's costing you energy and not saving you any. Good idea to switch to D mode for freeway driving. Anytime the brake lights are flashing, you're losing energy, so it's not a good idea to use B mode in all circumstances, all the time . . . . unless you're r e a l l y steady on the accelerator

Tell this to Musk.

 

[sirozha]

I own a Model Y and a Kia Sorento. The Model Y is new, and the only mode it has is a very aggressive regen (aka one-pedal drive) The less aggressive regen was removed from the Model Y on all vehicles manufactured after October 2020

So, I have to switch from one-pedal driving to coasting regularly. I so much prefer coasting to the point that I am ready to get rid of the Model Y. There are many things I dislike about the Model Y, but the lack of the coasting driving mode is the one issue I’m ready to dump the Model Y over.

 

[sirozha]

I wouldn't give up on it yet - One pedal driving is an acquired taste and it does take some getting used to. Once it becomes second nature though, most people prefer it. In 10 years with 3 Mitsubishi EV's, I'd venture to guess they don't have 50 miles total on them in any other mode but 'B' - Full regen. We drive that way all the time . . . . and I wish we had a max regen pedal on the steering wheel like Gen 2 Volts do

I actually got used to this many years ago with my little Kubota diesel garden tractor. It has a hydraulic transmission with a Forward/Reverse pedal . . . . and it also has a quite useless brake pedal nearby, which is mostly just in the way. Even though it weighs around 1,500 pounds, you can stomp the pedal and it will do a mini wheelie and if you need to stop in a hurry, you just reverse the pedal and it stops almost instantly, because it applies hydraulic reverse to the rear wheels. One pedal driving on a garden tractor!

It's nice to coast up to every stop and not need to use the brake pedal, but driving in traffic doesn't really give you the option to do that very often. You can lightly touch the brake and get regen whenever you need it, but that involves having a light touch while holding your foot up in the air or else you'll be getting some friction braking mixed in with your regen - If you drive this way all the time without consciously thinking about it . . . . the way you normally would in an auto trans ICE . . . . then you'll be getting a good bit of friction braking most of the time which is a waste of energy. The big thing that EV's and Hybrids give you that no ICE can match, it the ability to regain about 80% of the energy you used when getting up to speed from a start whenever you need to come to a stop

EV's get better around town mileage than freeway mileage because they recover most of this energy when slowing to a stop and because wind resistance (drag) eats up extra energy the faster you go. ICE's should be the same because drag still kills their freeway mileage too, but the tremendous waste of energy in start/stop driving really kills their around town mileage. The EPA mileage rating on most every ICE is higher for the freeway than it is around town - They use lots of energy to get moving and then when they slow or stop, they waste all that energy with friction braking and then have to use even more energy next time they start moving again. EV drivers should learn (one way or another) how to maximize this energy return we get when slowing to a stop - That (and slower speeds) are the secret to getting more miles of range than the EPA says your car is capable of

In the ID.4, the brake pedal invokes regen instead of friction braking unless you slam on it during emergency braking. From the perspective of pure physics, I fail to see how using regen instead of coasting saves more energy. If I can coast all the way to the projected stop and use regen at the end to come to a complete stop, how is this better than one-pedal driving from the energy-saving perspective?

I believe that Tesla eliminated low-regen mode because they didn’t want to design a hybrid braking system that invokes regen most of the time. Tesla seems to have friction-based braking only for cost-saving reasons. So, they decided to shoe-horn everybody into the one-pedal driving mode to improve range without having to equip their EVs with a more advanced braking system.

IMIO, the Kia / Hyundai system with paddles that control the regen level is the best way to drive an EV. I always gear down in my ICE vehicles and only use friction brakes after the engine braking removes most of the kinetic energy from the vehicle. To me, using regen paddles would emulate my driving style perfectly, while using regen instead of the engine to remove the kinetic energy from the moving vehicle. I would still use coasting at the lowest regen level available most of the time and would only “gear down” with the paddles before I have to stop.

 

[sirozha]

Well stated !

I hope that this concept is being taught in today's high school physics classes using EVs as an example.

The explanation I often use is that once you've paid (in kWH) to gain mechanical inertia ... conserve and use that inertia for as long as you possibly can.

You incur a hefty "premium" to convert mechanical inertia back into electrical energy ... and then into chemical energy ... AND THEN BACK AGAIN ... if you want to use it to regain your inertia.

I've driven VW "sticks" almost exclusively for 40 years; while I like the feeling of "B" the engineer in me cringes at the potential for inadvertent loss of efficiency.

Plus, don't want to be "That Guy" who is apparently "tapping his the brakes" on an otherwise clear highway for no apparent reason.

I DO use "B" ... but only when there's no other place to put the inertia.

Tell this to Musk. He thinks he is an engineer. He must have been chasing girls when they taught physics in college.