December 01, 2007
I have heard it said that the only reason the automakers make flex fueled vehicles is to satisfy their Corporate Average Fuel Economy (CAFE) standards. Well, let's look at that a little closer.
The CAFE system is run by the National Highway Traffic Safety Administration (NHTSA) and if you aren't very familiar with it, you might want to read their CAFE Overview.
Under CAFE flex fueled vehicles are given special consideration. Using an example from the overview, a flex fueled vehicle that gets 25 mpg on gasoline would be calculated to get 40 mpg. This is where the argument comes in that flex fueled vehicles are skewing CAFE numbers for the manufacturers. You can imagine all those flex fuel SUVs running around being counted against CAFE as if they were economy cars. But the CAFE rules have a maximum increase of .9 mpg attributable to flex fueled vehicles.
According to Cars.com for the 2006 model year GM's domestic car fleet averaged 29.2 mpg. The CAFE standard for car fleets is 27.5 mpg. Since GM's average of 29.2 mpg is higher than the standard of 27.5 mpg by more than .9 mpg, flex fueled vehicles did nothing in 2006 to help GM reach their CAFE requirements on their domestic car fleet.
It should also be noted that flex fueled vehicles may not have increased GM's numbers by the whole .9 mpg. As far as I know there isn't any place to go to find out exactly how much flex fueled vehicles helped the overall numbers for the manufacturers. So Ford with a domestic car fleet average of 28.2 mpg or .7 mpg higher than the standard may or may not have made it without the credits from flex fueled vehicles.
Of course in 2006 GM built flex fueled cars even though they didn't need the numbers to meet the standards. And they continued to do so in 2007 and 2008. Even though they don't need to from a CAFE perspective.
So the next time that you hear that the only reason manufacturers make flex fueled vehicles is to get around CAFE requirements you will know that that is not always the case.