Fuel

I hope that some one can give me some advise on what fuel to use on a '75 European 911S with a 76 2.7 engine.

I have asked around at the several "Experts" but I do not get a conclusive answer. while one mechanic is saying that therer is absolutely no problem to use regular un-leaded 92ron, another mechanic is saying, oh no you have to use the good old leaded higher octane fuel.

Can any of you help me out??

Thanks :-)

Joris
911S 75

You will never hear the end of that debate. I believe the 'specifications' for most all our cars allow regular gas. I believe it is 'supposed' to be oday for my car which has a 9.3:1 compression ratio. I use mostly Chevron Super.

Again, presumably regular is fine. But the penalty for using gas wiht insufficient octane, is detonation. A severe penalty.

I use a strategy of slightly rich mixture, ignition not too advanced and high octane gas. From there I could cheat a little on any one of the three and probably be safe.

If you want to use regular gas, it would be a good idea to make sure your car is tuned properly, and I suspect everything would be fine.

Higher octane gas does not have more power. It simply resists detonation better. Bruce Anderson wrote the best description of detonation I 've seen, by the way.

------------------
'83 SC

Most 911s from about 74-80 had a compression ratio of 8:1 which is fine for regular gas and should experience no detonation, after 80 they raised the comp to 9:1 which would require Premium Fuel

Thanks guys, for the advise. I guess smartest thing to do is just use leaded premium fuel.

Joris
911S