91 octane?

[adam2180]

Is it worth while using 91 octane gas in my 5 lug?

[Joels98taco]

i doubt it will make much of a diference with such a small engine with no upgrades. but try it if you want?

[whippersnapper02]

No.

[humanoid]

It wouldn't hurt, at least your wallet will be a bit lighter.

[adam2180]

I have always used it because I have been told its cleaner gas.

[98tacoma27]

I've got ocean front property in Arizona I'd like to sell ya.

[whippersnapper02]

It isn't cleaner.

[adam2180]

Originally Posted by 98tacoma27

I've got ocean front property in Arizona I'd like to sell ya.

I'm listening.......

[adam2180]

I filled it up with regular and didn't notice any difference.

[JDCPA]

The computer on the 4.0 engine differentiates between octane and adjusts its performance accordingly. THe 2.7's computer does not. Any octane in excess of 87 is wasted money.

[adam2180]

Yup, I'm a believer... Or a non-believer, you know what I mean.

[emt49126]

Originally Posted by JDCPA

The computer on the 4.0 engine differentiates between octane and adjusts its performance accordingly. THe 2.7's computer does not. Any octane in excess of 87 is wasted money.

Thank you. I put high octane in the other day. Needless to say, I complain that it costed me 30.00 for less then 9 gallons. What is your thoughts on gas additives?

[whippersnapper02]

Originally Posted by JDCPA

The computer on the 4.0 engine differentiates between octane and adjusts its performance accordingly. THe 2.7's computer does not. Any octane in excess of 87 is wasted money.

Only flex fuel vehicles have an octane sensor. All others rely on knock sensors or nothing but base maps. The 4.0 has knock sensors and it adjusts ignition timing according to how much knock is present. If your engine is excessively knocking on 87 then you have other issues.

[the.sight.picture]

im pretty sure its 89 octane if u are running the v6. I can tell the differance when driving...much less torque

[whippersnapper02]

Originally Posted by the.sight.picture

im pretty sure its 89 octane if u are running the v6. I can tell the differance when driving...much less torque

Sorry but butt dynos are not accurate.

[VanCity4x]

Originally Posted by JDCPA

The computer on the 4.0 engine differentiates between octane and adjusts its performance accordingly. THe 2.7's computer does not. Any octane in excess of 87 is wasted money.

I get 3+ mpg better using 91 on my 4.0. Ive been told the same thing. Wouldnt make a difference in 2.7L

[Desert Rat]

Interesting...

[Warhorseforever]

No. Search for the other threads present on the subject and read for days.

[lmikk12]

Sorry if i am a little late on this but octane ratings on fuel is how they stand up to pressure and heat before igniting themselves,with a higher compression ratio you have to run higher octane fuel so there is no detonation. higher octane fuel will not give you any more power if that is what you are looking for.However using a lower octane fuel can cause preignition or detonation or "knocking" that is small enough that you won't feel it but enough for your motor to retard the timing to save itself, this results in lower mpg's and less power. all it takes is one very small ping, so 89 or 91 would be more of a preventative measure than anything else. This can happen in any motor high compression or low even with higher octane fuel, but its what 3 bucks a fill up, why not.

[whippersnapper02]

Originally Posted by lmikk12

but its what 3 bucks a fill up, why not.

In some cases it can cause a power loss that's why not. Back in 2000ish when I used to subscribe to Sport Compact Car they tested a new Honda Accord V6 on 91 octane and they lost an average of 10 horsepower on the dyno runs. The car only called for 87 octane.