Incredible efficiency gains! What’s going on?

[Singletracker]

I have a 2023 R1T QM Adventure series with the 20” A/T’s. I’ve had the truck for just over two years and almost 24K miles. During the first year+ of ownership, I would have been thrilled to see 2.24 m/kWh efficiency. Overall, it was probably less than that. Over the course of the last couple of months, and especially this last month, my efficiency has skyrocketed. Per the truck data, I’m averaging 2.34 m/kWh over the last 8000+ miles and climbing. I have been tracking virtually every drive and I have it at 2.30 m/kWh and climbing rapidly. September has been amazing! I’m attaching a portion of my spreadsheet that includes September. Today, I knocked out 2.81 m/kWh, equating to about 362 miles of range on a 129 kWh battery. What is going on? Yeah, I know the weather this time of the year is ideal, but I have never seen this dramatic effect, ever. Rivian must be making some serious adjustments behind the scenes. What are they not telling us and why? If Rivian is the source of my good fortune, they should be bragging about it. Is anybody else having a similar experience?

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[Dark-Fx]

Traffic density and wind direction. For me, I get stuck behind school buses now this time of year, and they always drive slower.

 

[Rivian Owner]

Don't tell anyone, Rivian doesn't want ICE owners to know about the large magnets Rivian just turned on that pull you toward those large chunks of iron.

 

[Budman]

Your drives are pretty short. I see variations over short distances but over longer distances it is very repeatable.

this data was taken over a 3 year time span and two different vehicles

 

[Erik+]

Seeing significant gains as well. Had attributed mine to the new Goodyear Territory's I put on 1,000 miles ago and now, the obvious decrease in climate control usage. Went from the AT Pirellis getting roughly around 2.2 to 2.3, to now routinely getting 2.6 to 2.7 on around town drives, and the average since putting the Goodyears on sitting just above 2.5.

 

[Stainer85]

The same for me. I've been assuming it's the ideal weather. Yesterday, I was at 2.72 on a route that's usually around 2.4-2.45 over a distance of 34 miles, and I was driving faster than normal, with the windows down. I was driving a 2022 R1T with 21” Michelin, LTX M/S2 all-weather tires (no aero covers on the wheels).

That's a tiny sample size, I know. However, it's just a recent example of what I have experienced over the past few months compared to previously. My lifetime efficiency is 2.34 (spread over two sets of Pirelli tires and now the Michelins), as clocked by the truck. The truck has 54k miles on it. Varied driving. Sometimes spirited, sometimes with efficiency in mind.

Nothing scientific, but just a breakdown of my personal experience. Also, for reference, I live and do the majority of my driving in Northwest New Jersey with most of my mileage being up and down hilly roads and terrain.

 

[DD4ST]

Lot’s of variables: rolling resistance, internal gear tightness lossening with wear, wind, traffic, average speed, acceleration, etc. So changes with wear and you might unconciously be driving differently with more acceleration/regen. However, efficiency on the dashboard is a calculated number. It is possible Rivian tweaked the calculation somewhere in the past. This was rumored on one of the previous updates. It may be everything is the same but the number is more accurate. The only real way to measure is with actual power put in at charging vs miles driven for that power. The new energy display on the last update may help you suss that out.

 

[Singletracker]

In my situation, I’m driving the same way I always have, in basically the same situations. Some around town, some in the semi-rural area I live, often in the mountains, some on highways at 65-70 mph. I don’t use conserve mode. I’m normally in AP mode or sometimes Sport mode in the mountains. I’ve been driving it for two years and seen all the seasonal weather changes. I pretty much know what to expect on any given drive. The point is, over the last several months, there has been a rather dramatic change in efficiency, as reported by the vehicle. In the first year and a half of ownership, I never ever saw numbers even close to what I am seeing recently. Previously, I would have had to drive it off a cliff to see efficiency numbers like I’m seeing now. Something has changed with my truck, and it’s not about the weather or my driving habits. The truck reports miles driven and kWh used. I don’t see how the truck can somehow be calculating and reporting useage any differently. Miles are miles and a kWh used is a kWh used. Something has changed with my R1T Did Rivian do something to alter the tuning of the vehicle, in some way?

 

[mikehmb]

It's a golden time of year when we don't need heat/AC as much, but that doesn't explain the massive gains you've made. Very nice.

I used to see some significant variability on my QM, but nothing quite like that, unless there was a tailwind.

 

[zefram47]

Less use of temperature control with the HVAC this time of year. Also, tires will get more efficient as they wear. You may have also just learned how to drive more efficiently too. I swapped from the Pirelli AT tires to the Nokian nAT which is a heavier LT tire and I'm still more or less getting the same efficiency that I was with the Pirellis, maybe just a hair lower, but they're also 18/32nds new vs 12/32nds for the Pirellis. Honestly, the biggest annoyance on efficiency for me is my truck just not sleeping while away from home. It'll burn 1-2 kWh just sitting at work not moving because it doesn't sleep, according to the new energy monitor screens.

 

[mkg3]

If you have not replaced your tires, it most likely that your tires are wearing down and as soon as you replace them, you'll lose the efficiency gains. I have experience this on our Tesla and Rivian.

The wear lowers the unsprung rolling mass and improves efficiency (lower unsprung mass is better).

 

[Budman]

In my situation, I’m driving the same way I always have, in basically the same situations. Some around town, some in the semi-rural area I live, often in the mountains, some on highways at 65-70 mph. I don’t use conserve mode. I’m normally in AP mode or sometimes Sport mode in the mountains. I’ve been driving it for two years and seen all the seasonal weather changes. I pretty much know what to expect on any given drive. The point is, over the last several months, there has been a rather dramatic change in efficiency, as reported by the vehicle. In the first year and a half of ownership, I never ever saw numbers even close to what I am seeing recently. Previously, I would have had to drive it off a cliff to see efficiency numbers like I’m seeing now. Something has changed with my truck, and it’s not about the weather or my driving habits. The truck reports miles driven and kWh used. I don’t see how the truck can somehow be calculating and reporting useage any differently. Miles are miles and a kWh used is a kWh used. Something has changed with my R1T Did Rivian do something to alter the tuning of the vehicle, in some way?

Very unlikely Rivian did anything. The physics are the physics. There really isn't much (probably nothing) that a software update could accomplish. Starting battery temperature and motor temperature can have a notable impact as well as the ambient environment, tire pressures, tire wear, time since last charging session, etc. I've seen lot's of variation over short distances too. It might not seem like it but your trips are short! In your table many of the trips are less than 25 miles. That just isn't long enough for the vehicle to settle down into its steady state behavior.

 

[Singletracker]

Most of the comments regarding those items (tire wear, weather, driving habits, blah, blah, blah) that may impact efficiency, I agree with. I understand all that. I have over two years and 24K miles of experience with my R1T, so I know what the history has been and I have documented a lot of it. What has me confused is, how, in a relatively short span of time, the efficiency has increased so dramatically, to levels I’ve never seen before, without any change in driving habits. For instance, while tire wear may positively impact range over time, it would surely be a slower process. Yeah, the weather is nice this time of the year (happy truck), but it’s no different than it was last fall or the fall before. But, whatever it is, it is, and I am pleased as punch about it. Just thought I’d see if anybody else was having a similar experience.

 

[Time2Roll]

If you have not replaced your tires, it most likely that your tires are wearing down and as soon as you replace them, you'll lose the efficiency gains. I have experience this on our Tesla and Rivian.

The wear lowers the unsprung rolling mass and improves efficiency (lower unsprung mass is better).

Yes and the rubber hardens late in life and reduces friction.

 

[hudesigns]

Tire wear is most likely cause.

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