My GT is about to get off the boat in France...I'm wondering about what to fill it up with there? The fuel available there starts at 97octane...going up to 103....but all much higner than gas available at home..anybody know what this is going to do to my car? Anything I should do? Or are these numbers not rated like the US counterparts?

 

if its 97 octane, then HOT DAM!! these take 87, and they advise us not to use ANYTHING above 87. You might need a tuner b4 you even drive it.

 

Yea, I read that in the manual... seemed a bit strange. Since I'm not a 4.6L 3V "techie", would running premium 91 be detrimental to the engine?

I had never heard that about those octane ratings being so different than in the US. I'm wondering if the test methods are different and it is just a different scale (like metric vs non-metric, or Celsius vs. Fahrenheit), but chemically, they are equivalent. That would be an intersting research project. But, I'm just speculating.

Or maybe its just another French thing where they think they have to be better than the US.

 

Whatever you do, DON'T PUT GAZOLE IN YOUR CAR. Its diesel. They're trying to trick us! For the ratings, I dont know, sorry.

 

Yes.. the French need it for the sports cars over there:

http://www.austinev.org/evalbum/048.html

** French sux**= thats my cheap shot for today

 

If it were me, I'd be licking my chops.
The negative effects could be fouling of your plugs and check engine lights. Also, you will get a lot of carbon build up. To help remedy this, I would run more timing. With your car tuned to 97 octane, it will not only be much faster but it will also get really good fuel economy. Get it tuned to 97 octane. It will require you to trim your fuel curve and bump your timing, but just the $ you save in improved fuel economy will make it worth it.

 

I answered my own question on the internet...it seems they do measure octane differently..so looks like a non problem.

 

The ONLY difference between high and low octane fuel is the rate at which it burns. High octane fuel acutally burns more slowly. It is not as easily ignited which makes it suitable for high compression engines. Low octane fuel ignite very easily. So when used in a high compression engine, the low octane fuel will ignite simply from the heat inside the combustion chamber. This is called detonation, pre-ignition, or knock or ping. This notion of carbon deposits coming from higher octane fuel is rediculous. Using a fuel with octane higher than what the engine is designed for will cause no problems whatsoever. In fact, PROVIDED the engine has sufficient compression you would able to advance the timing and get more power. In a low compression engine, high octane fuel is just a waste of money. The 05 Mustang does have enough compression to take advantage of higher octane fuel but I am not sure of the stock computer will compensate on it's own. I think it would be neccesary to reflash the computer.
The only way you might get carbon desposits with a different fuel is if it had lead. I don't think leaded fuel is available anyhwere anymore but I'm not sure about that. You might want to check. Leaded fuel will really mess up your cats.

 

Don't you get some Ford factory support over there?? They should be able to sort it out for you, without question. I run 92 over here in my 05 GT, stick. There was a magazine article last month, where they showed, without a tune, 3-4 hp increase with the 92 octane over 87. They then tried racing fuel, 105 octane I think. It showed no improvement. They speculated that the knock sensors on the engine went into limp home mode, with the 105, since in the real world (USA) you just wouldn't get that fuel at a legal street fuel station.

It all made me wonder, if the whole test was a bunch of crap. But, it was out there anyway.

 

Enjoy your car and the 4 bucks a gallon...

Show the m frenchies the style of a real car