Well I saw (and posted) a thread about which octane you should run on. And they talked about that 87 was the normal for a Mustang. And here is my problem in Sweden where I live we only have 95,96 & 98 octane to choose from, so my question is if its bad to run on 95, and what I should do about it?

I have a -05 V6...

 

As far as I know, running on a higer octane won't do anything detrimental (other than maybe lower fuel efficiency). You just won't really see any kind of performance gains since the mustang is tuned for 87 stock. If you are still concerned about running a higer octance than what the car is tuned for, you should think about ordering an aftermarket tuner.

 

Isn't the rating system different in Europe? I thought 87 octane here was equal to 91 octane in Europe... or something like that

 

I'm not sure about the rest of europe but in Sweden we 95,96 and 98 octane gas.

 

Yeh the rating system is different, I'm not sure the details really. In USA ours is the average of two numbers and in most of europe its whatever the larger number is straight up. I do know their gas is still slightly better than ours though(not as far as numbers, but their lowest > our lowest, etc). 95 octane should be fine.

 

Everything you ever wanted to know about Octane - - and maybe a little more!

http://www.prime-mover.org/Engines/G...es/octane.html

 

If your octane is always higher there, then you absolutely must get a tuner to take advantage of the extra energy in the gas.

 

My understanding is the octane is not higher, the rating system for octane is different in Europe.

87 octane here in U.S. = approx 91 octane in Europe

The is off the top of my head from an old post somewhere it may have even been on this forum.