Just stumbled across this site today and found all the info and comments very useful! Just purchased my 2007 Prius 1.5 weeks ago after waiting for 2 months and loving every minute driving it!

I will be filling up my first tank of gas soon and was wondering if I should use 87 or 91 gas? Anybody have any suggestions?

87 is fine. Don't waste your money on 91.

Worse, there are reports of lower energy content in the 91 causing lower MPG too.

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
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