gas, which one is bestw Options

[rodriguez046]

Whats the best fuel to use on our cars?

[richee3]

Tune ups tend to do that

I'm kidding. Seriously though, I've run literally thousands of gallons through my Celica, all different octane ratings. The difference in how the car performed was never in octane rating; it was always in brand selection. Good fuels perform better, no questions asked. If the 91 you were buying came from Shell whereas the 87 came from a mom & pop gas station (no offense- I'm all for supporting small businesses) then that's why the car could have felt better. And once again, no offense, but the placebo effect has a lot to do with it. If you think you're doing your car a favor, you feel like it reacts better. Just like when I put the SS-III seats and TRD short shifter in my Celica, both Brigette I felt like the car was a lot faster when it was the exact same car behaving the exact same way. Premium fuel just costs a little more per gallon in a car designed to run on regular.

On the flip side, regular fuel in a car designed to run on premium can and will cause issues. My IS 300 requires premium and I went cheap, trying to save $5 one day, and filled it up with 87. Within a mile of driving, my check engine light came on and the ECU pulled timing until I basically had no power. Same thing with the BEAMS. I was not in a WOT position nor was I putting either car under heavy load, but both engine detected knock under average acceleration, which can and will damage your engine. But an engine designed to run on 87 will have no issues running 87 and will have gains that are a fraction of a percent by running premium.

Here's a good read: http://www.toptiergas.com/index.html

This post has been edited by richee3: May 5, 2012 - 2:09 PM