MPG WITH ETHANOL
 

I was getting 15-16 mpg around town in my 2008 5.3L Silverado. The gas here now is a 10 per cent ethanol mixture. With the cold weather and this mixture, I am now getting 13-14 mpg. Is this normal?

RE: MPG WITH ETHANOL
 

The cold will decrease mileage. But, so will ethanol. I used to be able to buy ethanol-free gas, but no more. I did have a difference when I tested the two, and I do get less MPG with the 10% ethanol blend.

If you look at the published mileage figures for flex-fuel vehicles, you see a big difference between gasoline and E85 MPG.

One example: http://www.consumerreports.org/cro/cars/new-cars/news/2006/ethanol-10-06/tests-of-ethanol-vs.-gasoline/1006_ethanol_test_1.htm?EXTKEY=SP72C00&CMP=KNC-CROYPICARS&HBX_OU=51&HBX_PK=pi
While this does compare E85 to gasoline, the same idea holds for “pure” gasoline versus 10% ethanol.