i have a question i drive 1993 z28 camaro an i know that the gas we are suppose to use is premium 93. anyway they are running out of premium an only have regular 87. how bad is it to keep running 87 regular in my car. also i have a hypertech chip installed as well.

 

i could be wrong but i think your car will just run like p!$$, and no damage will actually occur that isnt already being done by the fuel.

 

It'll just accelerate slower.

 

i believe it retards the timing. Who told you they are running out of premium? All gases are the same when they come out of the truck depending one where you get it (the cheap crap is like 10% water). They just add things to it after they put it in the gas stations to raise the octane levels. When i had my camaro and i couldnt scrape together the extra cents for premium id mix plus and premium. When you mix the two they even out to an octane level between the them which isnt nearly as bad as running regular.. believe me i ran regular in myZ when i first got it..

 

Now, who went and told you that you have to burn 93 octane?
The Gen II LT-1 engines of your vintage have a 10.5:1 compression ratio. They also have aluminum heads, which dissipates heat faster than iron heads. Plus the LT-1 engine has a reverse-flow cooling system, which circulates the coolant to the heads first. Both of these factors allow you to “get away” with using a lower octane than what an older Gen I engine with the same c.r. would require. So your "adjusted" 10.5:1 octane requirements aren’t as high as you might think.
Old non-computer controlled engines would give you the “marbles in the cylinders” ping sound if you ran lower than the needed octane level. Modern computer-controlled engines have a knock sensor, so that if you are using too low of an octane, the knock sensor will pick up the slightest ping and tell the computer to retard the engine’s timing to where there is no knock at all.
What causes octane knock in the first place, you ask? Lower octane fuel burns faster, whereas higher octane fuel burns slower. The knock is caused by the lower octane fuel burning too fast-too soon. The fuel fires too early before the pistons reach TDC, and causes the knock noise since it’s trying to push the pistons back down before they even make it to the top of the stroke. Constantly running with a severe octane knock can eventually do internal engine damage. But, modern engines purposely compensate for the octane rating so that running lower octane won’t damage the engine.
And.....contrary to popular belief, USING HIGHER OCTANE FUEL ADDS NO POWER TO THE ENGINE. What high octane does do (if the engine needs it) is it keeps the engine from de-tuning itself (via the knock sensor), which then results in a loss of power and possibly gas mileage as well. Simply put, high octane doesn’t give, but low octane can take away.
So, I would recommend you try mid-grade and see if you notice any difference, both in performance and gas mileage. You could even try alternating between low and mid grade every-other fill up. But if you don’t notice any difference, don’t waste your money.
BTW, my engine is just a shade below 11:1 c.r., and I alternate between mid-grade and premium with no ping or any other issues at all.

 

the owner manual said to use premium gas. if not the car wont run well.

 

*sigh* Did you read Camaro 69's post?

The car won't run bad, but it will pull timing and you will experience a decrease in power. See Camaro 69's post for the technical details...

 

Go back and read my response again. There's a difference between what is recommended, and what you have to use. It won't hurt the engine to not use premium. Like I said earlier, you can alternate your octane grades between fill-ups too. Unless you run your tank bone-dry before you fill it, you won't be running a straight blend of either octane anyway. Where you buy your gas makes a difference too. One of my old 69 Vettes was built with the engine having 10:1 compression. Most of the time i would run 87 octane without any problem. But if I filled up at the el-cheapo station, I would get pinging. Experiment, find a good station, and stick with it.

 

I can tell you for a fact that 69s right. I ran regular for the first fewweeks until i found out what it could do. Then i ran premium and it ranway better. After gas prices went up i started using plus and every so often premium and it was stillfine.

 

ok thanks for the info camaro 69.