Originally Posted by
kewldaddydave
Does it matter what type of fuel? I have run only E85 since I purchased my 2012 F250XLT FX4 6.2L in July. I now have about 2700 miles on it and only avg. about 10mpg. Is it really good to switch between fuels of 87 and E85?
Start using 87 and you will see about 2 mpg increase. It may take 1 or 2 tanks to get all the E85 out. IMO the cost savings per gallon don't match up to the mpg decrease of the E85, so I just stick with the 87 and only use Shell or Mobil.