High octane won't lessen performance you just waste money in a engine that is setup to run on 87. Most manufactures have mult timing tables built in the tune. So if the motor is spec'ed to run on 87 and you run 93 then your just wasting money as it will run the same. No some oil companies do have additives they add to the premium that does work to clean the valves and such. But actually its a waste of money too as most newer cars and trucks are direct injection now, so the intake valve never sees fuel anyway so the additives can't clean it.

If the motor is spec'ed to run on 92+ then it most likely a high compression engine 10:1 or better. If you run 87 in it, then when it "pings/knocks/detonates" (that should cover everyone's terms here if not google it lol). Then computer pulls timing and it defaults to the low oct timing table for a set time or till it notices higher octane and you have less power because it has less timing, that's it in short vs typing specifics out for the people that love arguing here. :rolleyes:

Gasoline direct injection is brand new to the market in the standard US cars. Gm just began using it in thevery last few years.

All the info some of you guys are talking about is related to computer controlled emission engines, which has nothing to do with the question at hand.... an old Kohler motor.

I think this thread is pretty much dead anyway as the OP got some "info" and "race day" has came and went....

Incorrect. DI has been 10+ years in the market for GM and isn't brand new. GM has had DI since 2007. DI has been in Pontiac, Saturn, and Cadillac etc for almost 10 years. Chevrolet began in 2010, so I guess that is a standard car.

So its more than a few years.


I just answered to correct some miss information a member posted to maybe help inform him, seems its ok for others to correct people with there knowledge in various threads. Whats wrong with that?

And actually the member had asked a question related to the topic at hand in his post. So not sure why its "dead"? If the members question is relative to the topic and may very well help another member out if someone is trying to do the same thing.

I suggest you look at a Kohler service or operator manual. Both say use clean fresh unleaded fuel that has octane of 87 or higher.

I was taught that the lead additive was use as a cushion/valve lubricated the valves/seats for longer life.

It is not used as a octane boster.

You are not the only one.

Interesting......Most of the fuel companies in my area have additives to clean valves and injectors in 87 octane. I see the same additive promotion on the pumps when I'm on the road.

I didn't look specifically at the kohler manual, but did look through the QL Owners manual here, pg 9

http://www.onlycubcadets.net/forum/s...ead.php?t=4670

My mistake, it doesn't say 89, it says 91 or higher for unleaded.

Again, I'm not arguing that it's needed, just curious why IH would suggest it. It only stuck out because I know it's not really needed. Since this thread veered towards octane debates, I thought I'd ask.

Next I'm going to get opinions on hydraulic fluid :ThumbsUp:

Yeah depends on the company. But interesting enough all base gas comes from same distribution point and they add the additives for each station when they fill the truck tanks. Had a buddy that worked at a yard for number or years. He also said that one of the stations did have there own tanks just for their own gas out of their refinery, I think it was Shell. But its been a long time ago.

Interesting read:
http://www.todayifoundout.com/index....d-to-gasoline/

Lead added to gasoline was initially for it's anti-knock (detonation) qualities.

Nothing to do with valve/seat lubrication at first offering.

Reference:

http://www.petroleumhistory.org/OilH...ges/knock.html

Shell, BP and Marathon are 3 big companies that come to mind.

You are correct about first offering.

The companies that built/design engines found out that they could use a cheaper material in the exhaust valve and seat when using lead. Cheaper material means more profit/lower cost of a product.