Hey i was wondernig which gas i can use?? I usually just use the cheap stuff cuz i dont want to spend the extra money. But............My friends dad has an L67 Riviera and the dealer said to "only" use premium gas. I don't know why my car would be any different?? I figured someone in here would know what and what not we can get away with..so all i'm wondering is if i have to use premium due to my car having an L67 */C.

I'm pretty sure 92/93 octane is recommend for sc engines. Your engine will run its best with this gas. I know somebody who actually owns an SSEi will chime in here, but if nothing else consult your owner'* manual.

We have talked about this a few times before.

In a nutshell: Yes, you DO have to run premium. At least 91 octane, depending on what is considered premium in your area. This engine is designed to work with the higher octane. If lower octane gas is used, you will get spark knock and the ECM will continue to retard the timing to get rid of it, along with your performance. You will also get poorer gas milage.

If you are low on gas and the station does not have premium, you could use a little regular or mid grade to get you to the next gas station. Running regular will work, but the hit in performance is the biggest problem. I can't say whether you will do long term damage to your engine, but I wouldn't take the chance.

Keep in mind, that even though you have to buy the expensive gas during this time of high gas prices, you are still better off than the peeps with SUV'* that get terrible milage and have to refill their 30 gallon tanks twice a week.

Jay

My NA does that too if i don't run premium in it. it also hesitates like an SOB

My car was brought to me in Las Vegas from Missouri. The guy driving it out kept records of the mileage on the 1400 mile trip at my request. He brought it here using regular saying he didn't plan on "getting on it". I immediately filled it with premium and have done so every tank since. My mileage now with premium (not to mention the performance) is enough better to offset the difference in price of the regular/mileage with regular.

Mine runs horribly on regular. I only put premium in it.

And for the saveing $$$... If your gas mileage is actually worse with regular, and premium os only -so much- more, you might be getting more mpg to make up for the price difference. Run about two full tanks of premium and see if it helps any in performance and in mileage.

Wow you guys just solved my bad gas mileage problem. ..haha. PREMIUM it is, for now on. No more late night escapades out to Taco Bell

...and besides, do the math here: The difference between mid-range (89 octane) and premium at our local BP/Amoco stations is 10¢/gal. If I drive in there on Empty and drive out with a full tank (approx. 16 gallons), I'll be spending all of $1.60 extra to get the Good Stuff instead of the mid-range. Heck, one beer at my favorite bar costs a lot more than that.

Say the premium raises your MPG from 20 to 22. That is 10% better. The difference in price is less than 10%, so you SAVE MONEY, and have more power. Win win if you ask me.

On my SSEi..on the gauge instructs..PREMIUM FUEL ONLY..I use ONLY sunoco 94 octane...I get 20-22 city...30-32 highway...WITH my foot in the throttle body!!