View Full Version : Marina only carrying 87 octane fuel as of this week

05-12-2010, 03:51 PM
Hello everyone,
I was wondering if anyone can tell me whether or not using 87 octane in my Corvette LT-1 engine will damage it. The marina is not carrying premium anymore because the demand is so low. I talked to the owner and he said that he buys gas that has no ethanol. The premium is expensive for him and he can't sell enough to cover his costs. I thought about using an octane booster but I was told that those have ethanol in them as well. If I bring gas from town, it all has ethanol of at least 10%. Bye the way, I have a 1999 Prostar 190 with 170 original hours.
I am really in a jam here about what to do. HELP.

05-12-2010, 03:53 PM
I would use the ethanol containing premium over 87.

05-12-2010, 05:05 PM
Thanks Chicago190. You think I'll do more long term damage to the engine with 87 than I would do replacing fuel system components? You're probably right.

05-12-2010, 05:07 PM
I'm with Chicago190, and add the Marine Stabil, or one of the other brands.

05-13-2010, 01:57 AM
You aren't going to kill your LT1 running 87 on one fill up. Will it damage the Lt1, no. Is it going to run top notch on 87, no. 89 or better is what the manual calls for, but you can get by on cheaper gas. You may notice lower fuel mileage or decreased performance, but that would be the extent of it. Put about half 87 in the tank if you are out and then go fill up a bunch of gas cans with 91 and you will be fine. I have had to run it with some 87 octane gas in a pinch with no issues. I definitely don't make a habit of it, but if if I am running low and that is all they have then I would rather run the 87 than paddle home.

05-13-2010, 11:08 AM
if the 89 was selling that slow and he discontinued it, more then likely it was closer to 87 anyways....

05-13-2010, 12:20 PM
...You may notice lower fuel mileage or decreased performance...

Yep, if conditions are such that pre-ignition occurs in the cylinders with the lower octane fuel. Otherwise, he will experience the opposite.

05-13-2010, 04:58 PM
I used premium most of the time with my LT-1, but when on trips to the Ozarks, I ran 87 almost exclusively for a week at a time. Never heard any pinging and honestly couldn't tell the performance difference. It was still a rocket down there at low altitude. I wouldn't worry about it.

05-13-2010, 05:29 PM
There "should" be no problem with the 87. The motor's knock sensor will retard the timing if there is any knock present. The 93 is just more resistant to preignition allowing more timing, but the reverse cooling system in LT motors does a really good job of helping.

05-13-2010, 06:21 PM
This subject is kind of funny to me. The octane level from 87 to 93 is practly a joke. Gasoline is a cleaner and a fuel and and it works the same in this octane range. The only difference between the octane level from 87 to 93 is burn time. The higher the octane the longer the burn will be. We are not running high performance race engines and 87 will be fine. If you put the 87 in I serously doubt that you could even tell any difference. You may loose 0.5mph top end and thats a maybe. I have also never ever seen an engine trashed because of using 87 instead of 93. On the fuel injected engines there are too many sensors that the timing will retard slightly and the air fuel mixture will be adjusted to compensate if needed and there wont be any pinging or detonation.

Here is a good test for you. I am sure that you run 87 in your truck or car. Next time you are at the pump fill the tank all of the way with 93 and test how much better the gas milage and how much extra horse power you gain. I guarantee that it is not worth the extra money at the pump for 93 and you wont win any more races on 93 than on the 87.

05-13-2010, 09:31 PM
Thanks everyone for your replies. So to be clear, most everyone thinks that 87 okay to use on a consistent basis with no damage and that I may notice a slight difference in performance and gas milage as the only side effect?