I had a 99 toy tac 2.4L before i bought my 2003 toy tac d.c. 3.4L. On the 4 cylinders i was told not to use premium fuel( 91 octane) in them because of their inherent carbon problem. Now that i have the v6 has anyone seen any reports or heard anything about premium fuel in these? Will i see any power and/or mileage difference? Or am i just wasting money? For the record, I always fuel at union 76, only way to fly!!

 

Unless you're running the S/C, don't bother with premium as the engine is rated for regular (87 octane) gas. And with the gas prices in CA, I'd shy away from the extra expense in any case.

 

I can't say I noticed any significant improvement. I went back to 89 & eventually back to 87. It runs great still, as far as I can tell and I'm actually saving money...never thought THAT would happen.

 

I run 89 octane in my 4th Gen with a 3.4L and it runs great.

 

I usually toss in some 87 because of gas prices. I occasionally throw in the 92. No idea why, but the engine seems to sound smoother with the 92. I still feel the same performance though.

 

Here's the big secret on what kind of gas to put in your car. Whatever the hell is recommended by the manufacturer. If your engine is supposed to have 87 in it then put 87 in it. If it's pinging on 87 then you have carbon build up, over advanced ignition timing, a lean air/fuel ratio, etc. Running 91 in an engine rated for 87 will not ever increase power output. There's one exception, if your engine has so much damn carbon build up that it needs 91 to not detonate. But, if you maintained your motor to begin with you wouldn't need to put 91 in it to make it run right and you could put 87 in it and you'd get the same power output from a clean motor.

 

87 here.

 

Isn't this a S.S.D.D. thing going on here?

Anything above 87 octane for a non-supercharged vehicle is unnecessary. :pat:

 

Some N/A vehicles require mid or premium with the ISR mod. I used to run 91 with the ISR mod to avoid pinging, but I am now finding out that mid works too.

As for you, go with what the other guys said.

Contrary to popular belief, you are not "treating" your vehicle to a tasty snack with premium.

 

Very true; however, you are treating the oil company to a tasty treat from your wallet with premium!

 

I tend to agree as well, the big oil conglomerates make enough money as it is.

Your owners maual should almost be your bible in maintaining your rig. I've been running 87 in my rig with no problems. I've also heard that if your engine gets used to the premium stuff and you go back to 87 or mid-grade, your rig will start to knock and ping. Don't use the premium unless your manual says so or if that wad of cash is just burning a hole in your pocket!