brandon9598

iTrader: (1)

Crap guys. I let my brother borrow my car yesterday and it was low on gas. It's tuned to only run on premium and I forgot to tell him. He filled it up with regular.. I put some gas treatment stuff in it. I've never ran it on anything but premium so is my car gonna be screwed up?

TheBlueKnight

iTrader: (4)

First off. What mods are on your motor and what octane was the tune set to run with? 93, 100?

brandon9598

iTrader: (1)

99 Z28 - LT's, ls6 intake, msd wires, slp intake kit, TB, and it was tuned to run on 93.

TheBlueKnight

iTrader: (4)

You do not need to be worried. I'm going to assume he put 87 in it? Detonation is only going to occur at WOT high rpm runs. You may notice, or he may have noticed that if he was flooring it, he may have heard some pinging noises.

All you need to do is pour a can of octane booster in the tank which you already did. For the majority of the rest of the tank don't go WOT or drive at high rpms, just drive normally. Personally I'd wait until about an 1/8th of a tank is left and then fill up with 93 and you'd be good to go.

Same thing happened to me. I bought my car from the dealer and they advised me they had accidentally filled up my car with 87. I had a 200mile drive back home. On the way home I stopped at a gas station and threw a bottle of booster in it and just drove normally.

brandon9598

iTrader: (1)

Alright. Thanks.

araber89

iTrader: (3)

Yep dad did the same thing with mine when he borrowed the car. Personally I think the car didn't run right over 3k RPMs and it just felt sluggish on power. It was fine to just drive normal. I only had it happen one time when I was below 1/4 on the tank of 87 that it didn't want to idle right for me. I put 93 back in and it started and the RPMs came up it found its idle and ran just fine. You should be fine.

Also I put Octane booster in and it didn't help. I later found out through research that you don't even gain a full octane value that you see on the pump. If its is advertised to gain 10 more octane values you get like .5. Also adding another one would only increase it to .75. So really you would be running 87.5 with one bottle and 87.75 with two.

If your really worried fill it up when it gets to half then again at half. This will dilute it enough. You should be fine and have no problems.

brandon9598

iTrader: (1)

Good haha. Cause it's running like absolute crap. Oh yea and one more thing. My brother told me he floored it after he filled it and it ran really crappy. Would that have messed it up? It isn't throwing any codes or anything just running super sluggish.

brianfromhawaii

iTrader: (3)

depending on who tuned it it could still have the low octane timing tables.. if those are there it saw knock and turned down the timing

teke184

iTrader: (5)

the computer should compensate to prevent damage.

you'll be better off topping the tank off several times with 93 to boost the octane as much as possible...rather than running it down to almost empty.

adding 5gal of 93 to 10gal of 87 yields 89 octane.