[llninja]

I got my Onstar report this morning

Fuel Economy: 84 mpg
Electric Consumption: 36 kW-hr/100 miles
Electric Miles: 864
Gas Miles: 703
Total Miles: 1,567
Percentage on Electric: 55 %
Estimated Gallons of Fuel Saved: 49 gal
Estimated CO2 Avoided: 958 lbs

The estimated gallons of fuel saved seems way off. If I take 864 electric miles and divide by 49 gallons, it comes out to 17.6 MPG. Had I driven those 864 miles on gas, I would have required far less fuel. Certainly they wouldn't be computing the 49 gallons based on the total miles, but 1567 total miles divided by 49 gallons is 31.9 which is closer to what I'm getting with my Jeff Gordon-like driving style.

So is Onstar just wrong here with claiming 49 gallons of fuel saved? Or are they assuming I'm driving a gas guzzler (which I was before I bought the Volt)

 

[bjrosen]

Onstar can't do even the simplest math, ignore all of their calculations, use the raw data and do them yourself.

 

[MikeyCVolt]

The only thing I can figure is that "gallons of fuel saved" might be based on the MPG of the average car. When I google average mpg for cars, 24.7 comes up. So the "average" car would use 1567/24.7 or 63.4 gallons of fuel. If your fuel economy is 84 MPG, that'd mean you used 1567/84 or 18.7 gallons. So you "saved" 63.4-18.7 or 44.7 gallons of fuel over the "average" car.

Sorta close, maybe. Depending on what they use for the MPG of the average car. The EPA says GM's fuel economy is 23 MPG and based on THAT figure, you get 49 gallons saved.

Mike