Dangerous Acceleration Curve in Conserve Mode

[AMaier]

I was driving in Conserve mode and accelerated hard to get up to speed. The acceleration curve ramps up over time in Conserve so it took a moment to reach the speed I wanted, which was expected. What was not expected was that when I reduced throttle input to stop accelerating, the curve ramp continued and it kept speeding up faster and faster even though I reduced from full throttle to about 1/3. This was an unintended and rapid acceleration that could have caused an accident.

I was trying to tell the car that I am done accelerating and would like to maintain speed, but it was still ramping up and giving me more power at a lower pedal position than it was giving me at the time I had it fully pressed.

Repo Steps:
• Find a private road you can safely drive on as you wish
• In Conserve Mode and at a slow speed (below 20mph) push the throttle to 100% (as if entering a busy road)
• Get up to speed (around 45mph)
• Over about 1.5 seconds, reduce throttle to 1/3 as if to reduce acceleration.
• Vehical continues to accelerate about the same or faster even though the throttle is reduced (this is where I would expect to not be accelerating nearly as quickly, if at all)
• Don't crash, drive safely

Note: I have driven around 20K miles in this R1T and am use to the acceleration in other drive modes. For me, this acceleration curve has only been an issue in Conserve mode.

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[AMaier]

I guess I expect the acceleration to reduce if I reduce throttle input. Due to the ramping up acceleration curve, rucing the throttle can be counteracted or exceeded by the time factor of the acceleration curve resulting in more acceleration instead of less. Acceleration is not a function of pedal position alone, and the time factor can undermine driver intentions (it is over dampened). Lower pedal position can result in the same or higher acceleration as time goes on.

One possible improvement would be to keep the current dampened acceleration while increasing or holding throttle position (positive acceleration can lag in Conserve mode), but clamp the dampened acceleration to a max of actual target position (acceleration can not be higher than the driver's actual input), and when meaningful thottle reduction occurs reduce the acceleration's rate of change until meaningful throttle increase occurs again (the acceleration can not increase as quickly when the driver might be trying to reduce their acceleration).

 

[CrazyOne]

In ICE car, if my acceleration is limited by TC, it will stay limited by TC till I reduce it to the point where TC intervention is not needed. Isn't this the same?

 

[jeeden]

I feel like Rivian should rebrand conserve mode to "reserve" or something similar. So many people use conserve mode all the time and I just don't think it's designed to be run that much and it's really just supposed to be a "oh crap I'm on the highway and I'm going to be short by x number of miles to my next charging stop instead of slowing down I can enable this mode for a little bit to get me there" solution

 

[brancky3]

I feel like Rivian should rebrand conserve mode to "reserve" or something similar. So many people use conserve mode all the time and I just don't think it's designed to be run that much and it's really just supposed to be a "oh crap I'm on the highway and I'm going to be short by x number of miles to my next charging stop instead of slowing down I can enable this mode for a little bit to get me there" solution

Completely agree. If I’m going to accelerate or decelerate at ALL, no conserve mode for me. It’s not worth the tire wear

 

[Donald Stanfield]

You shouldn't ever be applying 100% throttle in conserve mode unless in an emergency. That's not what that mode is for, it's for cruising and eco driving. If you need acceleration use one of the other modes until you are up to speed. Don't turn conserve on until you're already merged onto the freeway.

 

[Mathme]

Conserve mode is for loping along on the freeway to eke out a few more miles of range. On AT 20s, that range is only about 30 miles on a 100-0% charge. I'll take paying $2-3 more in charging costs on a road trip so I don't eat the front tires off my truck in 10k miles.

 

[Dark-Fx]

I would never call 1/3 throttle in conserve to be "rapid acceleration" regardless of speed.

 

[Prime]

You shouldn't ever be applying 100% throttle in conserve mode unless in an emergency. That's not what that mode is for, it's for cruising and eco driving. If you need acceleration use one of the other modes until you are up to speed. Don't turn conserve on until you're already merged onto the freeway.

Curious on a thread a while ago I remember some recommendations to only initiate conserve mode and go back to all purpose at certain speeds. Does this really matter? I try to initiate before a freeway on-ramp and go back to all purpose at slower speeds, but not sure if this matters.

 

[Tucker74]

Conserve mode is for loping along on the freeway to eke out a few more miles of range. On AT 20s, that range is only about 30 miles on a 100-0% charge. I'll take paying $2-3 more in charging costs on a road trip so I don't eat the front tires off my truck in 10k miles.

I got 356 miles in conserve on 20” ATs, it’s worth it on long trips. I don’t use it around town, but it does make a difference when you’re trying to.

 

[Donald Stanfield]

Curious on a thread a while ago I remember some recommendations to only initiate conserve mode and go back to all purpose at certain speeds. Does this really matter? I try to initiate before a freeway on-ramp and go back to all purpose at slower speeds, but not sure if this matters.

It isn't great for the truck to be driving stop and go in conserve and it accelerates tire wear.

 

[Prime]

It isn't great for the truck to be driving stop and go in conserve and it accelerates tire wear.

Oh no I just meant engaging and disengaging while moving vs being stationary, whether it matters.

 

[Dark-Fx]

Oh no I just meant engaging and disengaging while moving vs being stationary, whether it matters.

Doesn't matter, but don't do it under heavy acceleration or deceleration.

 

[BeanEW]

What was the state of charge? If it was high, the re-gen would not work. Although it might not be going faster, but it might feel like that because you expected the car to slow down.

I believe on Conserve mode, only the front wheels are re-gening. It might not slow down as fast as you wish. I experienced that when going downhill.

 

[AYAYRON]

I got 356 miles in conserve on 20” ATs, it’s worth it on long trips. I don’t use it around town, but it does make a difference when you’re trying to.

I've gotten as low as 220 in conserve mode with 22's (as high as 290) same route different days. It's not the conserve mode that matters it's the head wind/ tail wind, conserve mode does not add more than 10-15% range in ideal conditions.

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