I dont buy 91. I heard the j30 was designed to run off lower octane fuels, and putting in 91 actually takes away from the efficientcy and perfomance of the engine.
i use 87 octane..i get around 27-28...always fill up at around 400...and i just filled up at $3.21 and a total of $45.75....i hate driving these days...dammit but i love my car...haha
I don't know why some of you guys waste your money on higher octane fuel for stock engines, I've tried it in the past and felt no difference whatsoever...