There's no reason to waste money on lead additives. Your engine will run fine on regular unleaded without damaging the exhaust valves (as is the popular myth). Unleaded fuel has been available in the USA as premium unleaded for over 100 years.

I've never owned a modern car and all of my vehicles operate on unleaded fuel without additives, exclusively.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)