[Guest]

I have an '04 5.3L ECSB. When I got the truck from my dealer, he said be sure not to use 93 Octane fuel because it would be a waste of money. He said in the newer models ( like the '04) 87 Octane will make your engine run just as good as if you put 93 in it. He also said 93 could wind up damaging it. If i need to pull anything, he said i could go up to 89 octane if i needed to. Is there any truth to this, or is this guy full of crap?

 

[Whifflebat]

There is no point in running anything higher than 87 unless your manual tells you too, or its pinging, or you've got a higher octane tune. There is no difference in the quality of the gas, the only difference is that the higher octane gas ignites at a higher tempurature and is less prone to pre-detonation.

 

[Hit Man X]

Yeah, if you look at the timing charts for these trucks on the ECU stock...they could probably use like a 76 octane fuel there is so little timing! :haha:

When my truck had no tune, I used only 87...now that I'm tuned I use 93.

 

[Guest]

So whether I using a programmer that requires at least 91-93 octane or not, using 93 wont "hurt" my engine like the dealer said right?

 

[Hit Man X]

Nope it will not harm anything by using 91+ fuel, you may increase emissions as the fuel isn't fully burning but these are OBDII trucks so nothing to worry about there also.

 

[02denali]

emissions--what the hell is that. can somebody please tell me what emissions are???!!!!!!!!!! ha ha ha ha

 

[Silvlowrdr]

emissions--what the hell is that. can somebody please tell me what emissions are???!!!!!!!!!! ha ha ha ha

Emissions = :hack: Cats :read: