I was curious as to what grade of gas do others use in their Blazer/Jimmy??? I only use premium, 92 octane at the pump...

 

Cheapest I can get. I don't think our compression is high enough to need the higher octane

 

There is really no reason to run anything above regular on the blazers. They aren't high enough compression engines to warrant the use of higher octane fuel, unless the engines are modified or tuned

 

Unless the computer/engine has been tuned to advance the spark etc. to take advantage of it, anything about 87 is just a waste of $$

https://www.consumer.ftc.gov/article...ctane-gasoline

 

I've been running middle tier gas...89 octane, I reckon.

 

These engines were designed to run optimally on 87 octane fuel, but how many of these engines are running as designed still? What I have done with pretty much every one of my gasoline powered vehicles for the past 20+ years is run a 500 mile test of each grade from a single gas station shortly after purchase and routine maintenance has been performed. In a lot of cases, the vehicle had its best miles/gallon with 1 step up in fuel grade, but its best miles/$$$ was almost always at the manufacturer recommended octane.

Given an older engine where there may be deposits in the combustion chamber, the engine may run better on higher octane as those deposits can cause hot spots that then allow pre-ignition which the PCM detects as knock & backs off timing, diminishing performance. Every engine/vehicle/driver is different and I would encourage everyone to do their own testing.

 

I hope running 92 octane will not damage the engine over time lol!!! When I first bought it I used 87 octane but noticed it kinda had a "pause, hesitation" thing going on. I started using 92 octane and it has not done it since... I guess now I buy premium out of habit

 

Shouldn't damage anything, other than your wallet lol.

I've heard of a phenomenon with older vehicle called "octane creep," meaning that as the vehicle gets older, it accumulates carbon deposits, that can lead to pre detonation. The higher octane fuel resists this, and the car seems to run better.

 

I am at the point now that if I went back to the cheaper gas she might buck up and give me fits since she has been spoiled over the premium lolll

 

I seem to remember that my 1992 Blazer with that vintage Vortec could take either the 87 or 92 octane depending on how much power you needed from it; e.g. if towing use the 92. Might this apply to our 2nd gen Blazers too?