Hey guys. I saw somewhere that a 318 motor should take 10w30. Is that the spec for this engine or can I run 10w40? And will this thicker oil quiet down a little engine rattle (not much). Thanks in advance

 

10/40 would be fine at least in the summer. In NY I would probable use the 10/30 in the winter depending on the temp

 

I run Valvoline 20 50 most of the year with zinc additive "lucus assembly lube" and stp 3 oz per 5 qt the average daily temp here is 99 maybe 2 months out of the year it reaches 45 maybe
welcome to florida

 

I run 15-40w here. The only reason I am tossing M2C worth in is: Amarillo, Tx where there are definately SEASONS... 100's in the summer, 0 to -10 in the winters. Have had never had any issues. What "noise" does your engine make? lifters? on start or all the time? deeper start noise? goes away after start up? It MIGHT quiten it down but I would doubt it. IF it DOES then you are only fooling yourself that its "better". No its not 'better' its masked, and the problem still exists.

 

Since you live in NY, unless you are changing it seasonally, I would run a 5w/40 year round based on a mileage change interval. The 10w/30-40 makes no difference for your winter use, since 10 is the cold flow rating - same for either one. 20w/50 or 15w/40 is too heavy for very low winter temps and would cause more start-up wear if you ran it in winter.