Lead substitute in Gasoline Engines

[mike schafer]

1947 Mack 75 Fire truck with gasoline engine, Is a lead additive required in the gasoline ? I have used it for years I was told recently not so if using a premium fuel. I thought it is required to lube the valves regardless of fuel grade. Any one have an idea on this topic?

[Superdog]

I was told the same thing when asking about gas for my EF,said it wasn't needed,I put some in anyway,figgered it couldn't hurt.

[JTFormula]

I deal in classics cars and this question comes up a lot. I always suggest to just use premium fuel. The last Lead fuel was removed in the Mid 90's so for the past 20 years everything has been running on unleaded. If any damage was going to occur in a leaded engine still being used, it would have happened all ready. I had unrestored cars with lead era engines and ran them on unleaded with zero issue. Usually when motors are rebuilt they will install hardened valve seats to make them more unleaded friendly. You can add the lead additive if you wish, it won't hurt, but from my experience it is not necessary.

[farmer52]

As long as you don't run "full power" you should be okay without lead substitute. I think most HD truck engines had hardened valve seats.

[ajt3138]

1947 Mack 75 Fire truck with gasoline engine, Is a lead additive required in the gasoline ? I have used it for years I was told recently not so if using a premium fuel. I thought it is required to lube the valves regardless of fuel grade. Any one have an idea on this topic?

I run octane boost in my old car to make sure im getting premium fuel.