Gas additives

[money pit]

For low compression engines, do I need to add a gas additive. I heard that unleaded gas can damage the valve seats. I have a 318 in my challenger. Thanks

[cudabob496]

unleaded gas damaging valve seats is overblown, IMO, and
that of other racers.

[cudabob496]

I have however put this in my oil for 20 yrs. Restores cylinder pressure and power.

https://www.summitracing.com/parts/ror-00016

[jhaag]

compression has nothing to do with it. Lead is a lubricant, and if your heads do not have hardened seats, they will wear quicker with unleaded fuel. Has your motor been rebuilt? If so they have probably been replaced. 

[burdar]

What year are your heads? I think hardened seats started around 72? Even if yours aren't, I don't think these cars see enough miles anymore to really worry about it.

[money pit]

 The engine has never been rebuilt, as far as I know. It's a stock 318, 1973. Thanks for the info.

[burdar]

Your 73 would already have hardened seats for use with unleaded gas.