Corolla 2005 which fuel

[khvatov]

Hi all,
I own a corolla s 2005. I've always been pumping 89 (or the plus on some gas stations). I was wandering what octane number is preferred. The manual says "unleaded" but there is no recommendation as far as the octane count goes.
Any recommendations?

Thanks.
Alex

[JasonA]

Just regular 87 octane. There is no benefit in your enigne (or in mine) to running anything higher.

[bbsgarage]

Yes, putting anything beyond regular in a stock rolla is just wasting money.

[Rdkill]

I agree, I just had a few gallons of premium in my 08 this week and ended up getting LESS gas mileage than normal.

[ShadowR34]

Originally Posted by Rdkill

I agree, I just had a few gallons of premium in my 08 this week and ended up getting LESS gas mileage than normal.

really? hmmm.....its the opposite for me. i fill up regular, but every once in awhile i would fill up premium, and i see that i get a little bit better gas mileage. and i dont change my driving habits.

[Rdkill]

Perhaps my driving habits changed then...

[JasonA]

Any fuel mileage change with the octane of the fuel is coincidental, and not a product of the octane used. Various octanes of fuel have exactly the same amount of energy per unit. The only way possible for higher octane to cause an increase in fuel mileage is if your engine has severe carbon buildup, and the timing is retarded when running 87 octane to prevent spark knock.

Again, this discussion is related to engines which are optimized for the use of 87 octane fuel. If your engine requires an 89 or 91 octane (or higher), you very well could see a fuel economy reduction with lower octanes, due to the timing being retarded and general engine performance being reduced. But again, for engines like ours that don't require anything beyond 87, higher mileage on higher octane is coincidental.

[khvatov]

Thank you all for quick replies.
Alex

[REN69]

Your motor is a low compression motor, so yeah there's no benefit to adding higher octane fuel.

Only cars with motors with high compression OR with Turbo/Superchargers on them benefit from high octane as the fuel burns more efficiently on these cars, creating more power.