Montezuma

Jw best you can get arround here is 91

NewbieWar

91 should be fine, many people here use 93, ive never used 93 but it will burn cleaner and hotter w/ the higher octane... so it'll help on emissions to get a little hotter, and w/ high compression engines, they like the higher octain...

but i donno to answer ur question

OBE1 95Z28

I live in CA and all you can get is 91. My car runs fine for daily driving but I always use race gas if I'm headed to the track. Monitoring your knock sensor is the best way to tell if your car is running fine on 91. Octane helps to eliminate knock, your car's knock sensor system will retard timing to eliminate knock, thus reducing your car's power.

Montezuma

With some luck I accidently found 92 octane. Why don't they sell 93 in this state?

ninetythreez

91 is fine for an LT1 to run on for a long time. Just don't go with 87 octane ever. It will likely labor knock and ping. Especially on high mileage LT1s. The higher octane (91-93)is necessary due to the relatively high V8 compression ratio of the LT1.
I once ran 108 fuel from the airport with the other half of my tank 93 octane to see what it would do.LOL. That was in a 93 LT1 Z28 I had a few years ago with some bolt ons mods. It did NOT make a noticeable gain in power just by using half 108 and half 93 octane. Just thought I would share that with you guys.

ibanez6rg

You'll probably experience more knock with the lower the octane. But if that's all the higher you can get, you'll be OK.

anasazi

if your not knocking with 91 then you don't need 93. simple. end of story. kthx.

Buttercup

Exactly. Most people don't have the capabilities to monitor knock retard but if the engine is essentially stock, 91 octane should be just fine.

When I was tuning I found that my car ran better on the 91 octane Amoco I get in Iowa than it did on the 93 octane Kwik Trip gas in Wisconsin. I've got a cam to help bleed off dynamic cr but I've also bumped the compression ratio.

jasons93z

I use 87 octane sometimes with NO problems.

Mr Kevlar

I also have 91 in this area, the question is though will Power Programming of your PCM that says it requires 93 octane still work ok with 91??

Montezuma

Power programer is a waste of money, dosn't work,

JDBlaze85

87 octane is just being cheap. save a dollar. f*** that haha

93 ALL THE TIME
a little 116 on special occasions

ibanez6rg

First time I got my car I ran 87 and it ran like complete sh*t. Used 93 ever since then.

NewbieWar

lol nice birthday presents...

what does it do if its too high?
like say the whole tank was 110?

97WS6SCharged

The higher the octane level, the more energy it takes to get it to start burning. This means you can run more compression and more timing without having to worry about the heat generated by the compression causing the fuel to ignite early (detonation).

If you use gas that's too high in octane you could possibly burn up your pistons (especially stock pistons) because of how hot the fuel will burn. Also, you probably won't completely burn the fuel because it takes more compression and spark to fully burn racing fuel which will clog up your cats and may mess up your exhaust system. Bigger isn't always better.

By the way, 91/93 octane fuel will burn better/cleaner than 89/87 octane fuel and will give increased performance and gas mileage. So paying an extra 10 cents a gallon is worth it.