Ask Lobstah what super does for a car. I filled his tank on his car for him the week we were working on my car. The vibrations and everything went away. That was just on a old Forrester. Gas plays a huge part in the way your car runs.
Hell even in the rental cars I get I only put Premium fuel in them.
Is this a joke?
It's actually the opposite. Running premium fuel in a car that is supposed to be using regular yields no benefits what so ever. Let alone a huge waste of money.
And yes OP, you need to be using 91+ octane fuel.
I thought the same thing when I read it. Putting super in your car just for the sake of doing it is a waste of money.
To understand the reasoning behind adding super, you must really first understand what you would be using it for. First off, octane rating has NOTHING to do with performance fuel. Its not better, its not cleaner, in fact it really burns less easily. (Yah that's right, its harder to ignite) And that is the key to why we use it. Let me explain.
You really get the best performance out of the LOWEST grade fuel you can run (without knock). Without going into how a internal combustion motor works (I assume you know this already). What happens is: you start running regular through your car, and the since the fuel is easier to burn, the mixture of air and fuel in the combustion chamber detonates prior to the spark of the plug. (this = pre-detonation, IE: KNOCK). Presto your car starts pulling timing. SUXORZ!
By running a higher grade fuel that is harder to ignite, the car is less likely to fire before the spark. Thus running the way its supposed to. Race cars with higher compression motors, motorcycles, boosted cars fall prey to the need for higher octane fuel due to issues with pre-detonation. You rid yourself of knock by going up to premium fuels.
This is also the reasoning behind 91 and 93 octane mapping on cars. You make more ponies on 93 not because you are getting more out of the fuel, but because of its greater resistance to knock. You can push the tune, and the car further because of that.