20-09-2019, 08:33 AM
Hi Steve
Very experienced high mileage users on this Forum claim very adequate service from cheap multigrades. The 20-W is based on a quite low temp and 20W60 is thick at more normal temps and will sap “power”. For the first ten years of production cars would have run on non additive oil API SA. Then SB for some, this continued into the 1960s for most. Cyl wear was greater than today and main bearing wear notable in poor running conditions. Spenders may have in the later 1960s used the equivalent of API SC. Any modern oil (not necessarily classic replicas) will greatly exceed any of these API specs.
Engine wear in all cars greatly reduced from about the 1960s.
As it is likely the engine will devour some, and change intervals will be low in miles, fancy oils seem pointless.
Very experienced high mileage users on this Forum claim very adequate service from cheap multigrades. The 20-W is based on a quite low temp and 20W60 is thick at more normal temps and will sap “power”. For the first ten years of production cars would have run on non additive oil API SA. Then SB for some, this continued into the 1960s for most. Cyl wear was greater than today and main bearing wear notable in poor running conditions. Spenders may have in the later 1960s used the equivalent of API SC. Any modern oil (not necessarily classic replicas) will greatly exceed any of these API specs.
Engine wear in all cars greatly reduced from about the 1960s.
As it is likely the engine will devour some, and change intervals will be low in miles, fancy oils seem pointless.