Question about fuel additive and octane required

[cliff]

I was just reading the label on a bottle of chevron fuel system cleaner which I add every 3 months to keep the injectors clean and I noticed it said that using it reduces the need for higher octane fuels. I do notice added sluggishness after using the stuff and that compounded by the fact that my car is at 7000 ft does not help. It just seems that there is too much retard. Is it possible to use the fuel cleaner in conjunction with a lower octane say 89 oct rating and not have any detonation problems.

[snappy]

cliff.., read your cars manual.. regarding the minimum require RM2.. aka octain.. the genreal rule of thumb is the older the car the more likely it would benifit from higher octain.. my 86. has a minimum rating of 89 octain.. so adding 91 would not make it go faster.. the lower the octain the better it actually lubricates.. but the more "gunk" it leaves behind. after adding a "authority II " DME chip. I had to go to 92 octain.. without 92 octain I might as well remove the chip as it does nothing, but add 92 and it will give you the promised 15 hp.. I live in South California.. and we dont get higher than 91 Octain here.. so i have to make my own.. I have a formula for adding Xeylene and Taulene to up it to 94.. the differance is amazing,.. But it would be more that partly due to the DME chip.. those octain boosters you buy only adds "7" points to the octain.. so if youhave 89 octain to start with you would end up with 89.7. they are very pricey. But the injector cleaner is a great idea if you run on lower octain.. I might be wrong by I am almost sure that the only differance between the lower and higher octain is the ammount of "oil" added. Also rememebr that 89 at the pump is not always 89.. they get regulated to have an averrage of 89. so sometimes you wil get 90 or 88...
gl..

[divezic]

Also, the higher altitude you drive the lower the octane requirement. The gas stations in western Montana sell 89 octane as premium and I think 95 octane as the lowest grade.

My guess is that the Chevron fuel system cleaner claims to remove carbon deposits from the cylinder walls. These deposits cause "hot spots" which cause detonation or pinging. I don't think the cleaner actually raises the octane rating of the fuel in your tank.

If your car is detonating on a higher octane at 7000 feet, you probably have something wrong with your ignition that a higher octane won't fix.

[Blackfoot]

Originally posted by divezic
Also, the higher altitude you drive the lower the octane requirement. The gas stations in western Montana sell 89 octane as premium and I think 95 octane as the lowest grade.

now i'm confused. don't you mean it the other way around?

[divezic]

Me and my fat fingers.....

I meant 85 as the lowest grade.

I think it was 85.5 then 87 then 89 octane in the higher elevations.

[cliff]

Making your own 95 octane seems interesting. No, I am not getting any detonation, I just wanted to be safe and just get rid of some of that low end sluggishness. Thanks for all the replies.

[snappy]

cliff.. check your air filter and air hoses. I bet the problem would be there.. I would lean more towars it gettign to much air than to little fuel.. plugs/wires and rotors are next in line.. gl