I just got a 59 chevy step side with a 235.The farmer I got it from was using 15 w 40 for the last 20 years. should I keep using this oil or switch to 10w 30 or something else ? Thanks
Dear 59;
It's totaly up to you.
Multi grade oil is only needed in areas like the 'East Coast' where cold climates are the norm.
Generaly these engines use SAE 30.
Good luck, John M.....
if the motor went 20 years with out a problem i would keep on using it but the 10-30 would be ok too. dont know about the cold climate thing but i use 20-40 in the race motors that leave my shop. and are used on a dirt track.
I used to think that multi-viscosity oils were the way to go, until my engine rebuilder convinced me that the oiling systems were not designed for them. He recommended SAE 30. Period. Unless I was going to drive it in below zero temps.