What type of gas in a stock 305?

[LukeZ]

ive been putting medium gas in my stock 1986 305. I think it's 89 octane? It's a daily driver. Wanted to know if anybody uses the cheap sh*t (pretty sure it's 87), and if they've run into problems with it. Thanks

 

[jeremyandthemonte]

the higher grade gas the better and cleaner it burns now personally i don't run anything with octane other then my golf which seems to be happier with it

 

[pontiacgp]

It's not the octane I am concerned about. I don't use ethanol gas in any of my vehicles. With real gas my cars run better along with improved fuel mileage.

 

[Bonnewagon]

Cheap-*ss regular for me. No problems.

 

[jeremyandthemonte]

the higher grade gas the better and cleaner it burns now personally i don't run anything with octane other then my golf which seems to be happier with it

sorry i used the wrong word

 

[theoldsone]

I always felt I got more oomph out of my 307 olds when I put 89 probably because of all the carbon and clogged exhaust. If your engine has age put 89. MPG definitely went up though.

 

[Hunter Urban]

I run premium. If i don't, it valve knocks bad. Tried medium because it was cheaper. Not worth it

 

[foxtrot]

In a stock gbody, 87 octane should work just fine as long as you don't have carbon buildup & your egr system is in working order..

 

[Clone TIE Pilot]

I run plain 87, and it runs fine. My motor has a aftermarket cam and more advance timing so a stock 305 in good shape should be fine with 87.

 

[pencero]

Ethanol content is your primary enemy. If you use 89 your car will run rich. If you live where 15% ethanol content is legal you have to buy 89 everywhere that does not sell 'pure' gas. There are regional websites where you can look up who sells pure gas in your region. It is also important to ask which pump has the pure gas when at the gas station. I use regular and I add sta-bil. 89 runs rich and creates lag. Without sta-bil the ethanol becomes a problem if the car sits more than a few weeks and in cold temps b/c the ethanol creates water when it gets old which is why it can damage your carb, one of the reasons why*