Petrol question

Hi Guys,
I've just bought myself a 88 2.7 944, well chuffed :D
Quick question though, hope this doesnt make me sound too daft, but what petrol should I be putting in it? The previous owner said unleaded, but I just wanted to check to see what you guys would recommend.
Thanks in advance,
Bleech

premium all the way.

Okay not to threadjack or anything but I was just wondering the same thing...now I drive alot and really can't afford the high price of premium evry fill up, I try and run some through every 3rd tank..now is this bad ? on the gas cap door it states 91-92 octane..is this for a mechanical purpose? should I "only" be running premi? I hope I am not killing my car with 87 octane...it still works out cheaper to run a full tank of 89 octane and run a bottle of octane boost than running straight premi..this is only temporary untill i get back on my feet after nasty divorce..but I do notice the car loves premi more..

Regardz,
Jeremy

Regular Unleaded works just fine.

Notice it says 91 RON. When you fill up notice that the method of determining octane the gas companies use is something like this (R+M)/2
that's (Research Octane Number + Motor Octane Number) / 2. It's the average of two features of gasoline that make up octane.

More info here:
http://www.geocities.com/bmw535i86/text/FAQ/FAQ.11.html