I have a '93 SSE */C and on my under my gas hand on the dash it reads "Premium Unleaded Fuel Only", and inside the gas tank cover. One of my friends in my car club have a '98 SSEi and on his dash it reads "Unleaded Fuel Only". Did they improve the supercharger that much to the point you don't have to use 91 octane or higher?

I believe only the Series III allows lower grade fuel. Maybe on the Series II it was assumed or its printed somewhere else :?

I always run premium, but you don't have to. I've ran 87 octane in it and it ran just fine, just a little bit slower and my gas mileage went down about 3 MPG. So in the end it'* worth it to just run the premium fuel. BTW, the owner'* manual on my riv says to run premium, the gauge cluster says "unleaded only".

Just like my friends. Thats strange. I would figure with the newer models they would express it even more if you must use 93.

I don't know why it would say unleaded only.. out of room? Too lazy? Suppose to use premium if all possible.. I have tried down as far as mid-grade but as mentioned above.. the MPG dropped and no power there.. so it cost the same but I don't have to be so panicky bout not going WOT in case of KR and damaging the engine just to save a buck or two.

Yeah...if you can afford the SC...get the premium gas, a buck or two won't matter much, esp when comparing the consequences of not using it :?

Ya Bra.. Dat the Shiz Nitz cuz.. you speakin Da bomb ****.. lets go fo some Timmis HoHo'* and honk Da Horn in my 80K SUV eatin BK delight.. West Side East.. Word Life

Sorry

just had to.. remember 2F2F and Wassaga Beach..

Is running lower octane fuel in a L67 harmful to it? Or will it just affect performance and gas mileage?

Yes it can be harmful IF you go on the throttle hard and or a lot while runnin low regular grade gas.. the gas will predetonate ( before the pistons reach TDC which puts a lot more stress uneccassarily on the engine ) and cause KR ( Knock Retarde) which is bad.. it will affect performance and gas mileage tremendously.. I"ve tried it a few times just to see what happens..and needless to say.. you may think you save a buck or two at the pump to fill er up.. but your MPG goes down so bad that you have to fill up sooner.. which defeats the whole point. Stick with Premium.. and go mid grade ina pinch and baby it on the gas ( like a grandpa )

check out this topic http://www.bonnevilleclub.com/forum/...pic.php?t=6570

AS has already been said, ALL L67'* REQUIRE PREMIUM GAS! If you have an L67 it requires premium gas. If you run lower grade gas you will only hurt performance and gas mileage. Now if you were to put on a larger pulley so it runs less boost, install an intercooler and keep the same size pulley on or not go with one that is much smaller, or you put on a more effiecient blower, then you may be able to run regular gas with no detonation, and you will still get decent gas mileage, but that would be some $$$ that you had to fork out for those mods, so it wouldn't be worth it. For instance, now that we have put ~$7000 into the engine of the GTP we could run 87 octane gas on the street with no detonation with a 3.0 or 2.9 pulley. But running that size of a pulley would cost us a ~20hp loss, we would get worse gas mileage, and we spent $7000 to be able to do it, so what is the point in doing it. Nothing buy 92 or higher goes in the SSEi, and nothing but 93 or higher goes in the GTP, we like to keep our engines running good.