Classic car and non-oxy gasoline

I’m trying to use the non-oxy gasoline to avoid the 10% ethanol in reg gas on my collector car (1973). Just filled it up and it runs rough & idles slower. Does using non-oxy require carb adjustment, or is this bas gasoline

There’s no carb adjustment required between the use of oxy or non-oxy gasoline. You may have gotten a bad tank of gas. You might try adding a can of Seafoam to the gas tank to see if it runs better. If it does, then you got some bad gas.



Your 1973 model car should have no problems with the 10% ethanol gasoline…

They didn’t start designing fuel systems to handle oxy gas until 1976.


Non-oxy better, especially if gas stays in the tank for more than a couple weeks.

Thanks to all. On a related question, I’m learning about zinc content in oil, but it seems hard to come by. Is this a concern? Any recommendations?

The effects of truly bad gas would be much more extreme that a rough idle, like no idle what so ever. Bad gas is a often misused lable. I would look for normal tune up issues (and it is correct to use the term tune-up with a 1973), but just barely