Hey gang,

Just out of curiosity, what kind of juice are you pumping into your cars these days? I'm opting for the expensive "Super" High-Octane fuel, but with the pump prices these days, I'm wondering if I really need to. Somebody told me to pump regular, but every four or five fill-ups, go for the premium stuff. Any opinions?

1970 Fastback 302 2V

 

I run 91-93 whenever I fill up, it's expensive, but my motor pings a bit with lower grade fuel.

 

It depends on you compression and timing. Anything 9:1 or less you don't need premium gas.

 

depends how your engine is built if it doesnt ping/spark knock on the 87 octane use it dont waste your money on uneed octane.

 

i could put 87, she seems to run ok when ive done it before but i do notice a difference when using 91, its more rich and i get asmoother idle. cost more, but i dont mind

 

I always run 93 in mine when I'm not running CAM2, now that sh....ts expensive.

 

back in the day when these cars were made, 93 octane was "regular" and they suggested higher then that. Now a days regualr is 87 So i fill up on the highest octane the gas stations have, mostly its 91

 

I believe back in the day when regular was 97 octane they were using a different method to messure the octane levels in gas.

I have run 87 gas in my 289 with no problems. No pings. Try running 87 gas if it pings increase the octane.

 

I run 91 in mine, but it's not anywhere near stock. It runs fine even on the cheaper stuff, but gets a part throttle ping off idle without 91, and I'd rather not drown it with the power valve to cover it up

 

you dont have to run such high octanes all the time though, you can still run 87-89 on these older motors, you just have to advance the ignition timing some to compensate, so that the spark will ignite the fuel before the compression of the piston moving up will. I ran 93 for a while but its way too expensive for me now, so when i was on empty i filled it with 87, and just messed with the distributer until it was advanced enough to prevent the ping and it runs just the same as is did on 93. wont work for everyone, but for inline 6s and small blocks it should