Being in Europe I've been using the lowest octane fuel (95) in my GT without any problems. Someone told me that using 98 would be better. Could 98 octane damage the engine in any way?

 

HI there

Do you mean Octane 98 or RON 98?

As Octane and RON are two different types of way of measuring........

Here in the UK I use Shell Optimax which is RON 98 which is the equivalent to the US Octane 93 Premium fuel.

 

Overhere they call it octane.

 

Did you get your engine tuned for 95 octane? 95 probably works fine without a tune, but if you are trying to get the most out of the car, a tune would be more useful then upping the octane wouldnt it? I'm not quite sure on this, can anyone back me up?

 

The only mod I have Is a K&N intake, no tune. I don't want to screw around with the engine too much because there are no official ford dealers overhere who can fix mustangs.

 

If its not leaded you should probally be ok.