Just curious what octane gas are u using.
Please post your Milege Model Year and Gas

165K, Rodeo '95.5 93-Octane

IMHO, our engines aren't built for premium, so there is nothing/little to be gained by running 93.

My 3.2L SOHC has seen 87 all of its 130k miles (even some 85 on a few trips out west).

-Rob

Using 87 here, 93 trooper Ls 3.2dohc ....oooops and 152k

It might be just me but I always drive all my car with high octane, maybe I am just picky <img src="/forums/images/graemlins/drunk.gif" alt="" />

No, you are wasting your money. Higher octane gas is not "better" or more "powerful." Higher octane gas is designed to resist pre-ignition (knocking) in engines that require it. Using a higher octane gas in an engine requiring a lower octane rating provides no advantages, and most likely is is detrimental. To resist pre-ignition, higher octane gas burns slightly slower an has fewer BTUs per unit than its lower octane counterpart. This is mitigated in a high performance engine because the higher compression and other design attributes make efficient use of the fuel. In a lower performance engine, such as your 3.2, it can lead to issues with carbon build up in the combustion chamber because the fuel does not burn as completely as a lower octane gas would.

Good Luck,
Michael

Some engines are built for it, for example, my friends 96 Mustang Cobra 4.6 DOHC. It says in the owners manual must run '93 octance. Unless your engine is built for it (and i don't think ours are), you won't be taking advantage of the extra octane rating.

-Rob

You are right, It does says Regular 87 so from tomorrow it will be driven only with either 87 or 91 <img src="/forums/images/graemlins/kewl.gif" alt="" />

I don't know about that Rob.
I once put 87 in mine & it was sounding not like a diesel, but like it had blown something in it.

Ussualy i use 93 (sometimes 94).
It's a 3.2 '96 Rodeo with 69K.

rubo

Rubo is right. If your engine is pinging, a higher octane gas is justified. Newer engines should not ping (much), but emissions requirements push towards a lean mixture combined with advanced timing. When you add in things like air temp, altitude or load, you get pinging.

There is also a chance that Rubo got some bad gas. It happens.

Michael

What about 89 octane? I know 87 is recommended, but I have noticed when I run 87 in my 3.2 Rodeo it tends to ping under load, going up hills etc. I tried 89 and no more ping and "seems" to run smoother @ idle and under load. I have noticed black "soot" @ the end of the tail pipe though. Could this cause more harm than good and or being wasteful?

thx,
Dave