The 5.0 is rated at 360 horsepower (at 5,500 rpm) and 380 pounds-feet of torque (at 4,250 rpm) running on regular unleaded gasoline.
Burning E85 fuel boosts 5.0 engine power to 375 hp and 390 pounds-feet of torque.
Ethanol has a higher octane and heat-of-vaporization point than gasoline, meaning it combusts at a higher temperature and with greater force (higher compression) than gasoline, while also having a greater capacity to cool the fuel/air mix in the cylinder before combustion. This inherent efficiency is what enables the 5.0 to produce more power while burning E85 instead of regular unleaded fuel.
Even though E85 combusts with greater force, it has less energy per gallon than regular unleaded gasoline, so fuel economy is worse when burning E85
If you want to sacrifice fuel mileage for power, use E85.
Last edited by shortride; 08-03-2011 at 11:10 AM.