Originally Posted by dretired
I have seen in the 2010 ford towing guide.. e85 gets 10 more hp and more torque with the 5.4 engine..than reg unleaded
E85 may be cheaper per gallon but your MPG drops using it compared to regular 87 octane regular.
Also for some weird reason the truck book for the 6.2L gasser says you must run a tank of regular gas threw the engine before your maintenace check. Doesn't say why.