Originally Posted By: SUNRG
Originally Posted By: Sam_Julier
Volvo has a SB not to use 15W40 in this engine unless under extreme conditions. Most 15W40's have an HTHS viscosity of 3.7-4.0. So, I can't imagine running 15W50 with its 4.5 HTHS viscosity. Could it be the oil is too thick?
I run a 3.5 HTHS viscosity oil in my B230F engine. These engines do not require heavy weight oils.
Sam and BigD1 - I live in the mountains and this wagon is regularly loaded w 4 passengers, a full boot, 4 bikes off the back and a space case on top. If you asked a Volvo engineer if he thought a super-high performance G4 15w50 synthetic oil would work well in a 22 year old 240 under those conditions I bet they would approve.
Have you done or seen comparative UOAs in old 240s with various viscosities? I've had a lot of oil analyses performed and, all things being equal, in every instance I've seen thicker oil = less wear.
Beautiful setup - love the US1 rack. My 1993 245 has only 97k so I do not have a series of UOAs yet. Only read the Volvo Service manual and SB on 15W40. If heavy weight oils work for you than great. It wouldn't occur to me to run a 4.5 HTHS viscosity oil, synthetic or not.