Fuel grade

[Sparkey]

Just a general question to see what fuel grade every one is using with the 5.7l engine. With the compression ratio being as high as it is I have been reluctant to use anything but the high octane even though the book says 87 octane.

Thanks

[07 firecrew]

it is designed to run on 87oct, but since they have ethernol, i sometimes use 89oct

[brunski22]

there's another thread about this already on here. I was using high octane too but a guy on here explained that it actually is a waste of money and can rob the engine of power. Seriously.... Besides--those OPEC pr--ks get enough of our money.

[RLitwin]

You can check to see if higher octane is needed by checking your mileage with the different grades of fuel. You should get the best mileage with the octane rate best suited for your engine.

[impilot]

Also....at high altitude (above about 4500 feet), you can run 85 octane just fine. Here in Colorado our regular is 85...no knocking at all.

[asianflava]

Used everything from 85 on up to 89(with ethanol) I normally use 87. Never saw 85 octane before but since it was $3.35 (at the time) I went with that. Didn't have any problems. Had a slightly reduced mileage with the ethanol stuff but that could have been due to the headwinds I was driving in.

[LeeinAZ]

I did an experiment during a trip from Arizona to Arkansas pulling a 5800# travel trailer, a 3400 mile round trip. The first half of the trip I only used 87 Octane (88 in New Mexico) and on the return trip I used 91 Octane. I didn't notice ANY difference in performance and at best I only gained about 1mpg with the 91 Octane. It's 87 for me........

[JBK23]

well I have a 2006 tundra and use 87 when gas is really high
and need to save money and don't have not one
thing go wrong!

[JBK23]

may take time to get back to you new to site

[CrewMaxLTD07]

with high tech computers and fuel management systems.

I dont think it would really make a differnce.

the Trucks computer, computes and reads A/F mixture and adjusts
accordingly.. Does it not??

so using higher octane is flushing $$ down the drain.
I own a gas station. So it really doesn't bother me at all.

[use2vtec]

manual calls for 87 octane. Ive been using 87 octane since day 1 and will continue to do so .

[colt100]

87 here for me too. Never saw any advantages with going to a higher octane rating, except that in our state, the high octane doesn't have the ethonal added, which will help in gas milage. I can't see paying an extra 20-30 cents a gallon for 1-3 MPG gain. I just try and not buy enthonal treated gas if I can as I get better milage without it.

[NCFireFighter]

87 for me too spoke with several mechanics and engine designers all said if its design to run on 87 then put 87 in it, if its designed for 91 put 91 in it. So as the 5.7 is designed for 87 I have and will be putting only 87n in it!

[Henry T]

I have not noticed any knock using 87, thats what the higher grades do reduce knock or detonation in motors designed with those parameters. Stick with a good brand and get it from a busy station to ensure it is not too old.

I run Chevron fuel system cleaner evrey 3-4000 miles, its a great product keeps the injectors nice and clean, yes gas has detergents but this is a good idea anyhow.

[fla_guy]

87 for me. No reason to use anything else. All octane rating is is an anti-knock number. IF it isn't knocking, there is no reason to go up in octane, unless the manual says to.