[M2M]

Originally Posted by Forddan

Hi

I have a Tudor from January 1929.

Does this car have yellow metals in the transmission ?

In another thread of mine about STP it was mentioned that I have to be careful because it contains zinc anti wear ZDDP. And that supplement will affect yellow metals.

Can someone confirm me if I have to be worried if I mix 50/50 STP with 600w oil with respect to those metals. Unless my car do not have them and then there is nothing to be worried of.

Thanks
Daniel

Why are you complicating a simple situation? If you believe the 600w is too thin then buy a proper thicker oil; forget STP since it worries you. Buy Penrite Transoil 250 which is yellow metal friendly (GL-1) and use it straight or mix with 600W. A one liter bottle costs $16 at Restoration Supply Company.
https://www.restorationstuff.com/