Lead additive

[Jferguson]

Hi all! 72 lemans with 350 ci engine, do I need to use a lead additive when I fill up? I have been since I owned the car (3years), just didn't know if I had to so I have been. Thanks.

 

[melsg5]

Unless you are doing trailer towing or anything that constantly is putting the engine in stress you need no additive

 

[Jferguson]

Thanks! Does it hurt if I add some when the engine is not constantly being stressed? I just always thought older cars needed lead additives. Do 72's have hardened valve seats from the factory?Thanks as always for the help/advice/knowledge!

 

[melsg5]

The lead additive is a myth, in real world usage excessive seat wear is only observed in engines that are constantly under a heavy load. They started with hardened seats in 71 when the compression dropped for unleaded gasoline.

______________________________

 

[Jferguson]

Thanks for the information!