The W in oil specs

[OVERKILL]

There was a 20W-20 not that many years ago.


My 2¢

You can still find a 20W-20. Probably one of the best indications between the Winter rating and the hot viscosity, as they mean wildly different things despite being the same value.

 

[53' Stude]

There was a 20W-20 not that many years ago.


My 2¢

I have half a case of Pennzoil “with Z-7” additive from 1969 or 70’ in my basement. 20w20 and some 10w40