have any of you noticed a noticeable change i performance or noise or roughness by using 87 octane (R+M/2), rather than 93 or 91?

 

Of course... Your car should be more rough with 87, less hp/tq... less smoother...
I wouldnt recommend... If it happened, u better mix that with the highet Octane available.

 

Thanks, i had felt that after using 87 octane once that the engine seemed rougher and weaker but i wasn't sure if it was just me since i have only had the car for 2 months.

 

ya... it will make it feel rougher and it also isnt as good for the engine as it isn't as clean burning and stuff

 

The reason they give the minimum octane rating is because everything in the engine is tuned for a minimum octane rating. Its never good, especially in a turbo car to go below the minimum value. Especially only to save a couple bucks at a fillup.

 

ya... and will probably cost you more down the road when you have a problem if one comes up