High Regen vs Low Regen on Road Trip

[MrTopher]

I've lived my life in High Regen since taking delivery, but I'd ran into a Lightning owner a few weeks back at an EA charger when I was in my Mach-E loaner. We talked about a lot of EV items, but one of the items he'd mentioned was that he turns off his Regen when on a long drive and gets more mileage. Every EV has its own software and blah blah blah, but curious if anyone had done a mileage comparison using High vs Low. I'm about to head on a 350+ mile drive, but I can't compare it to the last time I'd done this drive cause the truck isn't loaded to the gills. But inclined to see if I notice a difference and report back using Low Regen, its mostly open highway with minimal traffic, but altitude increases from sea level to 9K ft (SoCal to Mammoth Area).

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[CarlM408]

Do you use cruise control on road trips?

If not, then turning down regen so you can more easily coast may help a little bit.

If you do, then it will do nothing at all.

 

[MrTopher]

Do you use cruise control on road trips?

If not, then turning down regen so you can more easily coast may help a little bit.

If you do, then it will do nothing at all.

Just ACC not Drive+, it's to jarring at times... I'll just enable it when I start and see if notice any difference

 

[ndmiller]

I'm not sure if High versus Low region is the amount or the speed at which region starts. High seems mapped inversely to the accelerated pedal (i.e. as you lift regen starts), while Low there is a delay to the start of regen when I lift.

BUT, I haven't a clue if that's really how it works, just how it feels when I tested both when I got the R1T.

 

[Riv E In]

This seems to be a recurring debate on here that gets lively and divisive.

While I don’t recall the scientific details (if any) from the last time this came up, there did seem to be overall consensus that you will get better efficiency with regen on HIGH in the city and on LOW on the highway.

Whether that is true, and if so the actual difference in efficiency, remains debatable…

 

[MrTopher]

This seems to be a recurring debate on here that gets lively and divisive.

While I don’t recall the scientific details (if any) from the last time this came up, there did seem to be overall consensus that you will get better efficiency with regen on HIGH in the city and on LOW on the highway.

Whether that is true, and if so the actual difference in efficiency, remains debatable…

This sounds like it would be the answer, because of the City stop and go, where the freeway is more rolling & coasting.

Hope this doesn't go off the rails like you'd mentioned it's had in the past...

 

[Riv E In]

This sounds like it would be the answer, because of the City stop and go, where the freeway is more rolling & coasting.

Hope this doesn't go off the rails like you'd mentioned it's had in the past...

Just don’t throw in the braking assist! That’s where things really get interesting lol

 

[Dark-Fx]

You get better efficiency driving so regen doesn't have to activate. (The exception being extremely long descents which don't exist in my area) Rivian doesn't blend regen in on the brake pedal though, so if you are touching the brake pedal, you're reducing your efficiency.

 

[Jonger1150]

If the brake peddle is used at all -- you're lowering efficiency. That's the only rule really.

 

[mkg3]

I've lived my life in High Regen since taking delivery, but I'd ran into a Lightning owner a few weeks back at an EA charger when I was in my Mach-E loaner. We talked about a lot of EV items, but one of the items he'd mentioned was that he turns off his Regen when on a long drive and gets more mileage. Every EV has its own software and blah blah blah, but curious if anyone had done a mileage comparison using High vs Low. I'm about to head on a 350+ mile drive, but I can't compare it to the last time I'd done this drive cause the truck isn't loaded to the gills. But inclined to see if I notice a difference and report back using Low Regen, its mostly open highway with minimal traffic, but altitude increases from sea level to 9K ft (SoCal to Mammoth Area).

I have posted multiple times on this forum that I wish Rivian gave us low regen option. Couple of firmware updates ago, it happened.

First, I do not use cruise control for the most part and drive 75~85mph on the freeways.

On my Tesla, there is about 10~12% range difference between Std and Low regen. The very reason why I wanted low regen on Rivian.

Your particular drive is not a very good comparison drive. It's gradual upgrade from Socal to Mammoth overall (few steep climbs, obviously). Which means there is little to no coasting going there.

Drive back is downgrade so you cannot get the affect of low vs high by itself. Both will brake and require input to maintain speed.

I just did this exact drive from south OC to Mammoth couple of wknds ago. Had a bike rack mounted on the hitch.

What I can tell you is that drive from Socal to the Bay Area, on 5, on All Purpose, low regen at 80~82mph, my R1S quad 22" OE tires got 2.15+ miles/kWh; whereas, the same drive in the similar condition (speed, weather, wind) on AP, Std regen got 1.9 miles/kWh.

I also have found that low regen at high speed on quad using Conserve mode gave worse milage than AP on quad. I don't know why other than two motors must work harder than 4 motors combined in terms of energy consumption and there is not enough regen to make up the difference.

 

[CrazyOne]

Do you treat Regen portion of the pedal like an on/off switch? If not, it shouldn't matter. If you do, it will. Assuming of course, the brake pedal is not used in both cases.

Also I don't see how low Regen would be better while using ACC.

 

[mkhuffman]

Rivian doesn't blend regen in on the brake pedal though, so if you are touching the brake pedal, you're reducing your efficiency.

Because of this, I would think high regen would be more efficient because you are less likely to use the brakes. I can see using the brakes a lot more with low regen, which will really impact efficiency.

And you can definitely coast using high regen - you just need to keep your foot on the pedal and gradually ease it back instead of lifting your foot off. It isn't hard. But I can see where that might be more tiring than lifting the foot away from the pedal.

The argument between high and low regen is tiring for sure, and a common one. The fact is if you drive exactly the same way, and use the brake pedal the exact same amount, there should be zero difference in efficiency. If you drive differently depending on regen level, it can make a measurable difference.

The brake pedal hurting efficiency is a big deal, though. You get nothing back when you use it.

 

[lefkonj]

The extra roll low regen would have vs the energy gained by high would be nothing at all. I can not imagine changing the setting would impact your range enough for you to notice. I drive in high region all the time.

 

[ndmiller]

Somebody test it out. Road trip a couple hours away on High or Low, try the other on the next day and compare.

 

[HaveBlue]

It feels like the lower Regen helps on the highway and yes we need to do a proper test.

Regen is useful because it captures energy lost by otherwise pressing the brakes. However neither Regen nor accelerating is 100% efficient. Heat gets generated both times in the motors and inverters. If you can avoid Regen and then later on the accelerating by just coasting, you are better off is my guess. The small ups and downs in the road and the imperfect foot of the driver probably means little bits of energy are getting lost along the way that coasting could save. A lower regen mode likely has a bigger coasting window. It's all I can figure as an explanation.

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