Thor Forums

[Sweetbriar]

50,000 miles of nothing but regular 87 octane fuel from whatever seller that had a reasonable price that I could get the coach in and out of with the daily drive towed behind four down. I've run the mountains of West Virginia and the flats strait roads that disappear at the horizon of south Florida. The rolling hills of the Great Plains to the twist and turns of the back roads of Maine. Never a knock, ping, misfire or hesitation. The only fault code ever triggered was due to a problem with the throttle servo motor.

The Ford 6.8L V10 engine with a compression ratio of 9.2:1 burning a higher octane fuel has no effect on the performance or power of the engine. If anything you could be losing power considering higher octane will slow the fuel burn rate. Only engines with high compression ratios can deliver all the potential energy from higher octane fuels and higher octane fuel is necessary with higher compression engines to prevent engine knock. You don't need the higher octane until at maybe 9.6:1 and that's even questionable.

Why Ford started to include the 91 octane recommendation after nearly 20 years of production is beyond me. The statement contradicts the first sentence of the section and a long history of a nearly bullet proof engine, "Your vehicle is designed,,,".