[obermd]

I have no idea where GM is getting the 3.5 mi/KWh number. It certainly doesn't match the EPA numbers:

Converting the numbers below:
2025 FWD: 3.2 mi/KWh
2024 FWD: 3.2 mi/KWh
2025 AWD: 3.0 mi/KWh
2025 AWD with 19 KW charger: 2.6 mi/KWh
2024 AWD: 2.6 mi/KWh

To do the conversion, simply divide the 100 miles by the KHw shown. I suspect GM and the EPA are reporting different numbers. GM is reporting battery to wheel and the EPA is reporting wall to battery to wheel.

 

[obermd]

So...if you take 319mi/90kWh = 3.54
For 2024, you use 315/90 = 3.5

I know GM says you have an 85kWh battery, but reality is that you have 90kWh usable.

Agreed. The interesting thing is that for the EPA numbers to work you have to have a 99 KWh battery for the 2014 FWD variants. This was one of the discrepencies I noted previously. If you assume an 8% KWh loss during charging, the the EPA's numbrers give you a 91 KWh battery.

31 Kwh Tot KWh
------- = -------
100 mi 319 mi

Tot = 31 * 319 / 100
Tot = 98.89 KWh => 99 KWh

 

[obermd]

That’s interesting.
Just for science, I used ABRP, which is usually extremely accurate for me, to estimate consumption going from Buckeye to Phoenix, which looks to be eastbound on I10 most of the way. If I use 100% reference speed, so no speeding at all, it gives me 3.5 mi/kWh. I usually drive 10% over the limit, so with that it would be more like 3.13 mi/kWh. I guess the wind must be helping that much that you can get an extra 0.6 mi/kWh or so.

That's less than 50 miles. I've yet to see a GM GOM or efficiency computation that's accurate for that range.