Could I possibly actually be getting 2.37 miles per kWh (422Wh per mile)?

[SwampNut]

This seems too efficient. But I've checked my math and spreadsheet formulas four times. I suck at math, but I think I've done it right. This is mostly highway, mostly 5-10 over the limit, with gentle driving and mostly conserve mode. Temps were mostly pretty hot with the AC at 73 auto.

This is data from a road trip (and I have a post to make about that also once I can confirm these number). I got my Rivian data from Rivian, so it should be very precise. I'm running aftermarket tires that we know are more efficient than stock (20" Nitto Grappler Recon). The Rivian data is read bottom up.

ChargeStartDateTime	SiteLocationName	kWh	Per kWh	Cost	Odometer	kWhPM	MPkWh
9/28/25​	End miles	120​	0.051​	6.12​	29762.18​
2025-09-28T13:58:55-07:00	Quartzsite, AZ - Main Event Lane	64.0831​	0.44​	28.19​
2025-09-28T11:01:36-07:00	Cabazon, CA - Morongo Trail	69.4981​	0.44​	30.57​	29398.25​
2025-09-27T15:19:08-07:00	Tejon Ranch, CA ‚Äì Outlets at Tejon Pkwy	34.0435​	0.44​	14.97​
2025-09-27T12:11:17-07:00	Coalinga, CA	79.495​	0.44​	34.97​
9/25/25​	Home charge	85​	0.34​	28.9​
2025-09-07T09:27:35-07:00	South San Francisco, CA - Oyster Point	29.2091​	0.46​	13.43​	28996.91​
2025-09-06T17:51:06-07:00	San Jose, CA - E Capitol Expressway	28.9973​	0.39​	11.3​	28951.21​
2025-09-06T15:04:48-07:00	Coalinga, CA	94.1704​	0.42​	39.55​
2025-09-06T09:49:37-07:00	City of Industry, CA - Colima Road	93.3118​	0.42​	39.19​
2025-09-05T14:32:16-07:00	Beaumont, CA - Oak Valley Village Cir	39.1428​	0.37​	14.48​	28547.05​
2025-09-05T11:44:29-07:00	Quartzsite, AZ - Main Event Lane	51.6973​	0.44​	22.74​
9/4/25​	Start miles				28179.04​
Gas price
Total		668.6484​		$284.41​	1583.14​	0.422​	2.368​

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[VandalSibs]

Think you have a typo in your title (should be 422 Wh/mi, otherwise you'd never be able to drive anywhere).

I was getting 2.74 mi/kWh on Sunday driving 3-5mph over freeway speeds in my Gen1 Dual Large Pack going west, and 2.42 mi/kWh going east. Was a morning/afternoon difference and winds do some crazy stuff on that stretch of freeway, but still pretty good numbers I'd say.

 

[petemill]

I don't think the calculations are entirely accurate unless you know you started calculating from your first row to your last row at exactly the same state of charge. A difference here of a full charge can change this down to 2.06kwh if I'm thinking about it right.

Also how are you measuring kwh in? Is it at the charger? If so, there will be losses before it gets to be stored energy in the car's battery. Which is fine if you want to measure total efficiency of energy from the grid to the miles on the road, but not the same as efficiency as reported in the vehicle's MPkWh.

 

[SwampNut]

Think you have a typo in your title (should be 422 Wh/mi, otherwise you'd never be able to drive anywhere).

LOL, crap!

I found the bad data. My formulas are good, I missed that there had been home charging right in the middle there. Since I used multiple data sources, I managed to miss those when moving data between sheets. My end result, now double-checked by someone with actual math skills, is more rational:

460wH/mi
2.18 miles per kWh

Upcoming post on an ICE comparison.

 

[smiffaz]

20" Nitto Grappler Recon more efficient than stock AT tires? Not stock AS tires, right?

Is there a resource somewhere with information about tire efficiency?

 

[SwampNut]

20" Nitto Grappler Recon more efficient than stock AT tires? Not stock AS tires, right?

Is there a resource somewhere with information about tire efficiency?

There’s a huge thread here about these tires specifically.

 

[azbill]

Back in 2023 I did a trip Phoenix to Tahoe and ran my 22 R1T in conserve mode. The outbound was in a lot of wind and rain, the return was very nice weather.

Phoenix to Tahoe in some rain and wind, used I-10 into CA:

Return trip, used I-40 instead of I-10:

 

[blturner]

You need to know that running in conserve all the time will wear out the front tires much faster. So much so that it can overtake the electricity savings.

 

[SwampNut]

You need to know that running in conserve all the time will wear out the front tires much faster. So much so that it can overtake the electricity savings.

We all know that, yes. I wouldn’t do that.

 

[blturner]

We all know that, yes. I wouldn’t do that.

The title of the thread seemed like a new owner question. If I had noticed your post count I would have known.
Sorry,

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