Guys,
I have no owners manual for the 89 Formula. It's a 350 TPI A4. In the 3rd gen tech forum the question was asked on what is the fuel octane requirements for a late 80's TPI and 50% said premium and the other 50% said 87 would do because of the low compression ratio.
So would you guys that have an owners manual and know the facts please tell me what is the GM requirement for octane in my car. I want to treat it right but if it doesn't need 92-93 octane why waste the money?

Thanks for your help.

Al

 

IIRC it recommended mid-grade or better, but let me give you some facts before you go out and use the cheaper stuff. These old cars run off of knock sensors. The cars run sooo much better with premium fuel that you can instantly tell the difference in both power and fuel economy. I won't be the first to tell you that anything under 89 octane is barely suited for your lawn mower let alone your baby.

I recommend that you also use a bottle of fuel injection cleaner at least once a month. It will keep the injectors from sticking and you will feel a difference right away.

If you need any help on anything or have any more questions please feel free to PM me.

 

AL,
I think it was covered in the above post.i definetly noticed a difference between running premium and regular in my car.It drinks nothing but the good stuff now.I know your car is a couple of years older than mine but I do have the factory manual( both shop and owners) if you need anything else.I aquired the shop manual by accident.When I left the dealership it accidentally fell into my trunk. Whoops

James

 

Hey thanks for the help guys. I'm going to do as you recommend and get some cleaner and switch over to premium an the next fillup. I drive the car back and forth to work and I didn't know what to use so it's been burning 87 for the last 1500 miles It doesn't seem to run bad and has no audible knock so I don't think that I hurt it. What the heck it's just one more on premium. 5 vehicles and 4 of them burn the good stuff. 2000 Formula, 98 SS, 98 GTP, and 89 Formula

I will be looking your way for future help as I fix this one up.

 

Like was said use the good stuff. If you need any parts for the Formula let me know as I may have what you need. I have changed every part on my drivetrain and have all the bolt on stuff. I also have some alt's and water pumps for the 88 up engines.

 

Thanks Chris, If I need any parts I'll holler.