What gas is everyone using...?

[Welshy]

I read the owners manual and it recommends using 87, 89 or 91...which covers all grades. Bit confusing, but having been paying premium in my last car I don't mind as long as it OK. Would prefer to do 89 or 87 though.

[CaliberSRT4]

Welshy wrote

I read the owners manual and it recommends using 87, 89 or 91...which covers all grades. Bit confusing, but having been paying premium in my last car I don't mind as long as it OK. Would prefer to do 89 or 87 though.

See the previous thread on this subject:
http://fiat-500-usa-forum.965414.n3.nabble.com/Fuel-question-td2650642.html

If you read that and still have a question, you'll have to be more specific.

[Welshy]

Thanks Caliber....that's perfect.
Cheers.

[Gavin]

So a run down (lets see if I get it at all):

City driving...go 91 for maximum fun. 87 if you are a soft on the pedal.

Twisty mountain driving...go 91. Period. :)  If you aren't driving this car hard and fast in mountain twisties, well why the heck not.

Long highway trips...87 is fine...higher is fine too, but you won't see much gain in performance nor mileage, so going cheap is ok.

89 seems always an option in any situation.

I do almost all city driving or mountain driving...will likely always use 91 unless I do a trip out of state...then likely 89...

Gavin

[RacerRon]

The reason Fiat is recommending high octane gas is because the car has a high compression engine and you will receive top performance by using the high test gas. The reason behind this is that high test fuel is less susceptible to pre-detonation, or pinging. With older engines, if you heard pinging or knocking from the engine, bad things would happen if it continued and your pistons won't be very happy. With the newer, more sophisticated engines the ECU will compensate for this and will cut power to avoid the pre-detonation. Using regular gas will most likely not hurt your engine. But, if it's 100 degrees outside and you are climbing a hill towing your monster truck and you hear pinging, then it's time to put the high test gas in.

PRE-IGNITION DAMAGE