DISadvantages to higher octane fuel?

[Scrufdog]

Instead of asking if higher octane is better, as the old question goes, I ask this. What are the disadvantages of higher octane fuel?

The Burb is designed for 87 octane, but would higher octane have any negative effects? I'd like to know because the grocery store I shop at offers 10 cents off per gallon for every $100 you spend. With a family of 5, I generally see 70 cents off per gallon once a month at fill up. Figure the extra 30 cents for higher octane fuel isnt a big deal.

 

[someotherguy]

Yes. Higher octane means less volatile - so it's harder to ignite. Higher compression engines don't have a problem with this, they are the reason higher octane fuels exist. However, engines with lower compression ratios have a harder time burning this fuel. You will make less power and possibly even lose a little MPG, though both may not even be a measurable amount, at least not in the variable conditions outside of some crazy test lab. What will be measurable though will be the amount of money wasted buying fuel your engine doesn't need and can't properly use.

Richard

 

[Scrufdog]

Thats what I figured. Figured I'd ask anyway, real life opnions are always nice.

 

[TylerZ281500]

Yes. Higher octane means less volatile - so it's harder to ignite. Higher compression engines don't have a problem with this, they are the reason higher octane fuels exist. However, engines with lower compression ratios have a harder time burning this fuel. You will make less power and possibly even lose a little MPG, though both may not even be a measurable amount, at least not in the variable conditions outside of some crazy test lab. What will be measurable though will be the amount of money wasted buying fuel your engine doesn't need and can't properly use.

Richard

that exactly^

 

[someotherguy]

You could throw a chip in there that wants higher octane fuel, if you don't mind paying for the fuel. It would have a more aggressive timing advance curve and would wake up the ol' Burb a little bit. Might be a little tough finding a chip these days especially with your combo - 5.7/4L80E, I'd assume most probably had the lighter duty stuff in mind.

Richard

 

[TylerZ281500]

i used to mix a little alcoohol in back in the day, to clena everything out, last time i did it on a tbi i blew out the headgaskets though.

 

[GMRedline]

Don't most people agree you can advance your timing 3* at the distributor on 87 octane with a stock setup? You should be able to run more with high octane right?

 

[someotherguy]

I disagree about bumping up base timing beyond zero at all, on 87 octane. I used to think 2-4 degrees was OK until I drove around with an OTC Genesys hooked up and saw knock counts and knock retard...since then I keep them at zero.

Richard

 

[TylerZ281500]

i wouldnt mess with timing unless your dealing with a not stock motor. for stock leave it and run regular gas.

 

[IOWNJUNK]

i used to mix a little alcoohol in back in the day, to clena everything out, last time i did it on a tbi i blew out the headgaskets though.

Now the gov't does it for you, how cool is that!!!