Test results: E85 vs. gasoline

This chart shows how our 2007 Chevrolet Tahoe performed while running on E85 and gasoline in three fuel-economy tests and overall, in four acceleration tests, and in three emissions tests for gasoline vehicles.

The great E85 fuel hunt

The scarcity of E85 fuel in the Northeast made testing our Chevrolet Tahoe more of a challenge than we had first anticipated. We quickly found there are no commercial stations in Connecticut, where our auto-test center is located, where we could fill up with E85. The only E85 pumps we could locate were owned by the state of Connecticut, and the fuel wasn't for sale.

After a call to a representative of the state's alternative-fuels program, however, we found that the state buys its ethanol from a supplier in Alabama. So we contacted the supplier and arranged to have 220 gallons of ethanol shipped to us from South Carolina by truck in four 55-gallon drums.

But that got us only the pure denatured ethanol. To use it in the Tahoe, we had to blend it with gasoline in an 85/15 percent ratio to create E85. For that, we again turned to the state and arranged to have a fuel expert come to our track and help us blend the fuel by hand.

The whole process took the better part of a month to complete and vividly illustrated why advertising flex-fuel vehicles in most of the country is currently an empty promise.