Single Pedal Driving - Why Not an ICE Feature?

[Magicbus]

While at the dump today (sorry, Town Recycling Center) a fellow in a Jeep told me how much he liked the look of our R1T and was asking me about having an EV. One thing that i really like is single pedal driving. My wife drives a Volvo 90 Recharge Hybrid and, although it took me a while to figure out, it can be set up for single pedal driving and even has a setting for No Creep when stopped. Even when the engine is running it behaves exactly like the R1T, which makes switching back and forth much easier.

So it begs the question... since most all ICE vehicles have computer control of braking for anti-lock, our Rivians use the disc brakes when the regen can't do enough, and Volvo handles the braking and creep even when not running on electric, why don't many ICE vehicles employ "automatic" braking via the accelerator pedal?

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[Nixapatfan]

No thank you, I enjoy driving, hating everything going with automatic transmissions this would just take away all remaining joy.

Only reason to tolerate 1 pedal drive on an ev is because of regen.

 

[iamnid]

It could be done but would be hard on the brakes as well as less efficient in an ICE because it would negate the ability to coast.

 

[TexasBob]

Had a Mercedes EQS SUV rental loaner for the past week without OPD. Both of us HATED it. (Worse, it had creep as soon as you take your foot off the brake.) You had to select max region on each drive and even then it was not true OPD. 100% with you. Soo much better. But I do not think it would work nearly as well as a synthetic braking deal. The ability to lightly feather the regen is an electric thing.

 

[electruck]

cost and complexity with no benefits and at least one drawback. plus, the majority of drivers would complain and turn it off simply because they don't want to change how they drive.

 

[mkg3]

First, I like 3 pedal driving the best. Going to two pedal was a hated but necessary adjustment for me once I needed a family hauler. Until then, every vehicle I owned had a manual box.

At first, OPD was a novelty and felt kind of interesting and neat. After a very short period, I found it liking it less and less to the point that I wished all EVs had a better regen control settings so that the vehicle can coast and stop using the mechanical brakes, if the driver prefers. Not all that concerned about energy recovery on EVs.

As for having OPD on ICEV, engine braking can do most by downshifting gears in the transmission automatically (as long as its not a CVT), since many vehicles have rev matching features these days to downshift on both true manuals and double clutch transmissions (DTC). Still, the driver will probably have to apply the brakes the last 10~20mph to control the actual stopping point.

Today, I own 2 EVs, 1 PHEV w/DCT, and 1 ICE vehicle. I go back and forth between all of them. The best thing about my DCT vehicle is the regen for the battery occurs in the 8 speed transmission and is not a part of the brakes at all, leaving the natural feel for the brakes. I never feel the regenerative action by the motor and keeps the battery charged under normal driving without having to plug it in.

Several EV automakers blend regen with mechanical brakes. When the driver steps on the brake pedal, the regen is used first, then mechanical brake takes over. This approach allows the vehicle to coast (hence increasing range) and leaves the driver with the normal braking behavior and the feel.

 

[CANCERDOC]

Because EVs get something from the regen aka you put a little juice back into the battery. For ICE vehicles all you’d get is unnecessary braking wearing out the friction pads.

 

[CrazyOne]

It's inefficient, even on EVs. Coasting is significantly more efficient.

I am used it it, and can drive smoothly with it, but I still hate it after 3.5 years. I especially hate the part where it uses max regen at lower speeds using only front wheels. They almost lockup in the wet.

 

[DanielEV2023]

While at the dump today (sorry, Town Recycling Center) a fellow in a Jeep told me how much he liked the look of our R1T and was asking me about having an EV. One thing that i really like is single pedal driving. My wife drives a Volvo 90 Recharge Hybrid and, although it took me a while to figure out, it can be set up for single pedal driving and even has a setting for No Creep when stopped. Even when the engine is running it behaves exactly like the R1T, which makes switching back and forth much easier.

So it begs the question... since most all ICE vehicles have computer control of braking for anti-lock, our Rivians use the disc brakes when the regen can't do enough, and Volvo handles the braking and creep even when not running on electric, why don't many ICE vehicles employ "automatic" braking via the accelerator pedal?

Single pedal driving makes sense if an inverter is charging a battery which is more efficient than friction braking. Coasting is more efficient than friction braking and traditionally the driver is managing that mix to drive smoothly. So without a proper inverter single pedal driving it does not make sense.

 

[hudesigns]

Engine braking does not provide enough drag for 1-pedal driving design unless involving real brakes, which makes it more inefficient.

On EV side, regen only improves efficiency if it normally requires braking anyways. Otherwise coasting is more efficient. That’s why EV is more efficient in city less so on highway.

 

[ElGuano]

The way I understand it, one-pedal would mean more brake use, and significantly worse for efficiency. Not sure why it would benefit ICE at all.

 

[hudesigns]

I think for EV 1-pedal driving utilizes electric motor’s reverse drag to slow down motion and charging battery simultaneously (to kill two birds with one stone, so to speak). At this point motor behaves much like electric generator. It does not make sense for ICE vehicles.

 

[mkg3]

Engine braking does not provide enough drag for 1-pedal driving design...

Just to clarify, it depends on how the transmission gearing is and engine braking is implemented.

Today's automatic with L2, L1 definitely is not sufficient. If the transmission is programmed with engine rev matching, it can shift down the gear ratio such that it can slow the vehicle down. In other words, if cruising at 70mph in 8th gear, it can downshift rapidly to 4th, say, with engine revs matching what 70mph is in 4th and slow it down. The rate of deceleration is not all that different than taking one's foot off the accelerator pedal on EV's OPD.

All that said, I see no need for ICEV to have OPD.

 

[hudesigns]

Just to clarify, it depends on how the transmission gearing is and engine braking is implemented.

Today's automatic with L2, L1 definitely is not sufficient. If the transmission is programmed with engine rev matching, it can shift down the gear ratio such that it can slow the vehicle down. In other words, if cruising at 70mph in 8th gear, it can downshift rapidly to 4th, say, with engine revs matching what 70mph is in 4th and slow it down. The rate of deceleration is not all that different than taking one's foot off the accelerator pedal on EV's OPD.

All that said, I see no need for ICEV to have OPD.

Correct. What I try to point out is that EV 1-pedal using electric motor’s inverter behavior is so strong that it can quickly slow vehicle down to standstill which replaces most braking needs in city driving. ICE car’s intelligent gear shifting can’t do this without involving brakes. It might explains why there’s no 1-pedal design in ICE vehicles.

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