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Gas Additavites

Just bought a 1955 Ford with a small v8 engine. Should I add a lead additative on each fill up?

I would. By the way, nice car!

I know this isn’t your everyday driver. So how often will you fill the tank? So not a big expense! I would also add a can of fuel stabilizer at each fill-up. Again not a big expense!

But you must be warned. If you use a gasoline that contains ethanol, it will eventually damage the fuel system. This is a 1955 vehicle. And the fuel system was never designed to handle the corrosive nature of ethanol. So if possible, only run non-oxygenated gasoline in the vehicle.


I agree on the ethanol warning but a lead additive is not needed. Research has proven that lead was never needed to prevent wear to the valve guides in any vehicle. Unleaded gas will not harm an older vehicle as I have used unleaded in both a 55 and a 57 Chevy since unleaded came out. This was one of those government mandated policies that was never needed in the first place.

The lead substitute doesn’t prevent valve guide wear. It prevents the valve seats in the heads from being pounded out from lack of lubrication that lead provided. Unleaded fuel engines have hardened valve seats.


Lead is not needed to protect your engine. That’s urban legend stuff. Amoco sold unleaded 100 octane premium for many years when your “Y-block” was in its heyday. It was clear as water…These old engines needed valve jobs every 50-60K miles no matter what kind of gasoline they used. In your case the camshaft bearings would rotate, cutting off the oil supply to the rocker arms. Your engine has solid lifters by the way, requiring periodic valve adjustment. The valve covers are easy to remove so you can check the valves and rocker oiling easily…They made external oiling kits to overcome the problem of the rotating bearings…

I knew that the Ford “Y-block” engines sometimes had problems of oil starvation to the rocker arms, but I didn’t realize that it was caused by the camshaft bearings rotating. I assumed it was due to the oil passages becoming sludged up. What you say makes sense, since the oil feed to the rocker arms went through the camshaft bearings.

We had wonderful inexpensive solutions to potentially expensive problems in those days. The outside oiling kits were one such solution.

Caddyman,where were you when we were discussing the virtues of modern engine technology over engines from the era you speak of? We had posts glorifying many multiple hundreds of thousands of miles on these “gems” of technology.

Any idea if it has had any engine work in the last 30 years? If so, it probably had hardened valve seats installed for unleaded gas.

No sure, but I doubt it. How about adding Marvel Mystery oil on fillups?

Thanks for your input guys. Since this is going to be a “weekend toy” i probably won’t fill up that often. I just wanted to do what ever is necessary for the good of the engine. My thought, how about adding Marvel Mystery Oil to both oil & gas?

I would suggest adding a product like ZDDPlus to the motor oil in order to prevent extreme wear of the camshaft. Modern motor oils are great, but not for older engines like this one!

Thanks for the info, i’ll see if i can buy it locally

I would not worry about lead substitute. I would, however use fuel stabilizer to help with the Ethanol problem, especially if you are using gas that may contain up to 10% Ethanol.

Use 15/40 “universal” fleet oil which will meet your engines lubrication needs without additives. A little Marvel oil in the GAS can’t hurt…Your BIGGEST problem will be keeping the points based ignition system tuned up…

Any suggestions?

I would add it IF the valve seats have not been replaced with the updated ones.

You did not tell us how much you intend to drive it nor it’s current condition so other issues that we might be able to offer suggestions for well… any suggestions are made based on some guesses of the writer.

I will probably drive it 20 miles a week around town only.Current condition, 62,000 runs ok. Not sure if the valve seats have been replaced but I kinda doubt it.

Sta-Bil is the brand I use, but any brand of gasoline fuel stabilizer would be fine.