Is it possible to put mid-grade in a stock LS1 or will mid-grade make it ? I know not to put the low octane gas in it but is it permissible to put 89 mid grade in?

 

93 octane

 

OK. That's what I thought.

 

not worth the extra money you'd be saving, it would be only $1.40 max anyways ($0.10 more for 91 @ 14 gallons)

 

also you'll get better gas mileage by running super, so it may end up being only $1 in savings

a gas station put 87 in my car once by accident. absolutely disgusting.

 

the computer has fuel maps for any grade of gas. you may not get as aggressive timing and such with the lower octane possibly costing you some ponies. but yes it will run fine on 87. i personally have run 93 since i got my car and my tuner copied the 93 fuel map in place of the 87, so even if the computer tried to revert back to the 87 table it would effectively be going to the 93 table. it doesn't know though

 

not hijacking the thread but, what's the highest octane we can run without a tune?

 

93 if your state offers it. Anything higher than that is usually sold at special stations and a very high price. I used to pump 95 octane at the track when I had my thirdgen (had the timing increased but didn't notice better track times with the 95 octane, wasn't necessarily tuned for it) but it was like $4 a gallon and that was when 91 was about $2 a gallon.

 

Why these keep coming up I don't know. The ecu does not know what you pump in. It only reacts to knock.

Will you get knock with 89 or 87? Not all the time and sometimes never depending on the conditions. If you are going to Granny putt around in cold weather but never go fast or use higher rpms. You may never get knock. But why have an LS1 then?

Me, I use the power of the engine all the time. I will always use the best gas I can get!

 

From what I've seen the LS1 could be run on less octane,
certainly if you tuned it conservatively and kept the temp
well controlled. For a stocker, and '00 was the lean year so
they say, it isn't something I'd cheap out on. Ping now, pop
soon enough.

 

I was on dead empty and stumbled into a gas station that had nothing but regular. Pissed me off, but I put a little in and peddled around a couple days with no issues. The entire time, I didn't drive it nearly as hard and wasn't tempted to romp at all. Looking at it like that, maybe it was a good thing for me to run that garbage.

 

i think it would take a while for it to do any major damage, but if you're really that worried about saving money on gas you shouldn't own one of these cars. when i had regular in it, it took about 3/4 throttle to get it to downshift going up hills. i think i only went WOT once just because it felt so terrible everywhere else i was afraid of what would happen. filling it up with super after that was one of the "mods" i have ever done.

 

I never run anything but 93...mistakenly put 87 in once and the car ran like crap.

 

and when you get this knock it starts to revert to the low octane table giving you a more conservative tune. so in a way it does kinda know doesn't it?

 

I only run 93 in my car....

 

Not saying you but if a person cant afford to put high Octane in the car they should be driving something more economical.

 

doesnt matter what you put in it. If you put 87 in and you start to knock it will retard the timing hence loss of hp. but it wont mess anything up. Also the prices here for 87 are 2.20 and 2.55 for 93. I believe it would be cheaper in long run to run 87 but less power. you would get less mpg but you could be buying two more gallons of 87 for the same price. so if you bought 14 gal of 93 it would be same price as 16 gal of 87.

 

Not true.

Your gas mileage gets worse as it goes up in octane.. Octane is a rating of combustion, the higher, the harder to ignite.. So more spark is needed for a more complete combustion. If you were to put a lower octane, more easily combustible fuel in it, then it burns more completely and gives better gas mileage.

 

^^ rite rite,, but run 93 anyways

 

for anyone that wants to run less than premium in their car, i strongly recommend that you hook up a scanner and watch your knock sensors go nuts. every time they go off, that's pre-detonation EATING your motor (albeit, maybe not in large bites).
do whatever you want, just see for yourself what is going on in your motor instead of taking someone else's word for it. hell, you could plug in, go WOT a few times and find that your car runs fine on 89...
even on the stock tune, my car was pinging a little on 91 octane (highest octane i can get at the pump where i live) on a hot day.