Off Pavement Range Expectations

[Dman250]

I know this topic has been covered but I find “data” all over the map. My expectation is that for dirt/gravel road use at 25-40 mph, occasional stops, up and down moderate grades, range impact should be pretty minimal from the much higher rolling resistance. I’m not talking about hard-core rock crawling or flying along at Baja 1000 speeds. Given low average speeds I’d hope range would be similar to a 60 mph highway drive given much lower aero losses.

But I’ve seen some pretty low range numbers from R1 owners? What should I expect?

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[Jeremy3292]

It will be very good, over 300 miles, if you’re going that slow unless you’re scaling a mountain and putting a lot torque on the motors. If you’re just going slow then yeah it’ll be top range.

 

[2kwik4u]

I did an off roading event with NERC over two days in spring of '25. This was in Northeast PA, was pretty technical and with a big group.

Here's the pictures. https://photos.app.goo.gl/1YEWz43h2shdjfoX6 You should compare these to what you'll be doing. I suspect it's more technical than you're describing, so slower speed/more torque, but only you can judge that.

I averaged 0.827 mi/kWh while going 26.78mi off road. Roughly 158mi range with my dual motor (non-performance) on a full 131kWh charge. It took us two long days to do 26mi, so it was largely a non-issue in terms of capacity vs journey.

Here's the data.

I've done this trip 3 times, and logged all of the data. Be happy to pull other sessions if there is interest.

Also, check out this guy on YouTube. He has some great videos on range and being offroad. Likely a better fit for what you're asking for.

https://www.youtube.com/@MotorsportUnplugged

 

[JacobAZ]

At 25 - 40 mph I assume the dirt road is pretty hard packed, maybe washboard, but not mud, loose sand or thick gravel. So, if it's like our typical forest roads in AZ, you will get good range, similar to city driving. The wind drag difference from 40 mph to 60 mph has a huge impact on efficiency/range.

 

[Mathme]

I think it really depends on elevation gain. We were in our conversion van in WA in July and one road we were on was about 20 miles, but we had over 5,000 feet of elevation gain. in an EV, that sucks serious electrons and you will gain some coming back, but not nearly as much.

In the truck, I've driven fairly regularly from Placerville up to South Lake Tahoe on Hwy 50 doing the speed limit. This is about 6500 feet of elevation gain and going up it's going to take about 35% of the battery, while coming back down the same road at the same speeds, it'll take about 15%. Even at slower speeds, on gravel roads, it's hard to effectively predict how much energy you'll use.

My recommendation: Start with as full of a battery as you can.

 

[mroe]

I budget 1.6 mi/kwh off road based on my lifetime tracking

 

[usulio]

Dirt roads 25-40mph? Very good range. Not at all comparable to off-roading at 5mph.

 

[JacobAZ]

I think it really depends on elevation gain. We were in our conversion van in WA in July and one road we were on was about 20 miles, but we had over 5,000 feet of elevation gain. in an EV, that sucks serious electrons and you will gain some coming back, but not nearly as much.

In the truck, I've driven fairly regularly from Placerville up to South Lake Tahoe on Hwy 50 doing the speed limit. This is about 6500 feet of elevation gain and going up it's going to take about 35% of the battery, while coming back down the same road at the same speeds, it'll take about 15%. Even at slower speeds, on gravel roads, it's hard to effectively predict how much energy you'll use.

My recommendation: Start with as full of a battery as you can.

Yes, climbing in any vehicle takes a lot of energy and down takes little. But in the R1 (and all EVs) the regen is quite amazing. If you are going round trip the regen pretty much takes the elevation out of the equation. Round trip mountainous up and down drives at highway speeds have only a little less overall efficiency as flat roads at similar speed and weather. Example: Peoria AZ to Heber AZ round trip 320 miles. Total energy used in mild to warm weather 120 kw. = 2.66 miles per kw. Same speed on flat ground 2.75 - 2.8 miles per kw. Same result over dozens of drives on this route.

 

[AdamEk]

The Mt Washington Auto Road is a great showcase for regen. 4618 feet of elevation gain over 8 miles. Used a lot of power going up in my Model Y. Gained almost as much back on the way back down. Averaging the two was very close to the typical energy usage for 16 miles.

 

[usulio]

I have also found that elevation pretty much cancels itself out to what flat driving would have been once you get back to net 0.

 

[Dman250]

Would it be fair to expect regen to be less effective off-pavement due to more energy being absorbed by the rougher terrain?

 

[ksurfier]

I know this topic has been covered but I find “data” all over the map. My expectation is that for dirt/gravel road use at 25-40 mph, occasional stops, up and down moderate grades, range impact should be pretty minimal from the much higher rolling resistance. I’m not talking about hard-core rock crawling or flying along at Baja 1000 speeds. Given low average speeds I’d hope range would be similar to a 60 mph highway drive given much lower aero losses.

But I’ve seen some pretty low range numbers from R1 owners? What should I expect?

Between 3 and 5 times less efficient than on road driving depending if it’s hard packed or more loose/sand/gravel/soft/mud:

At 65 mph, using a 5,000-lb vehicle as an example:
* C_{rr}=0.010, smooth road → about 6.5 kW
* C_{rr}=0.015, coarse pavement → about 9.7 kW
* C_{rr}=0.025, hard dirt → about 16 kW
* C_{rr}=0.050, gravel → about 32 kW

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