Mid Grade Fuel

[Irhmsd]

I may be nuts, by my 2002 Limited seems to run much better on mid grade than premium. When I use premium, I often experience lumpy idle at traffic lights. Never seems to happen on mid grade. Anyone else have this happen?

 

[THatfield]

I run 87 all of the time. Purrs like a kitten. I do run Chevron Techron fuel system cleaner every 3,000 miles to keep the fuel system clean. But my fuel grade is regular 87 unleaded.

 

[SweetWaterSurprise]

On a stock truck that's not SC, there's no real reason to run anything other then 87. Aside from personal preference.

 

[T4R2014]

On midgrade as opposed to premium? Or did you mean midgrade as opposed to regular? Try a tune-up. The 5VZ should be able to run smoothly on 87 octane.

 

[JayRolla]

You dont need to run premium but I see no reason that it would cause rough idle. Ive fully tuned out ecu's before and higher octane never causes an issue. Crazy.

 

[SweetWaterSurprise]

Premium around here can vary from 91 to 93 depending on the station. Generally it's 87-89-93 in Jersey at most stations, but I see the occasional passing off 91 as premium. Used to love when Sunoco had Ultimate 94. Ran that in my 911 Turbo until they got rid of it.

 

[Kryptoroxx]

In some areas like mine where I get bad fuel I run nothing but premium because it's the only one that doesn't get messed with.

 

[SilverRidgeRunner1]

I've never noticed a rough idle using 93, I have been using it sense day one and have always seen a improved fuel economy with using it. Kinda strange you getting a rough idle from it.

 

[KatRider05]

I was actually talking to my dad last week about this same thing. He is a Toyota Master Technician for the last 34 years. He said that 87 octane fuel is perfect for city/highway driving. Use 89 octane fuel for when you have a heavy load i.e. towing or full of cargo. As the cylinder/piston heats up under load you will need the higher octane fuel. He also said that is the primary function of the Knock sensor, to help keep the timing.