Jack Roush has teamed up with Valvoline and has come out with a full synthetic 5W-50 which meets Ford WSS-M2C931-B @ $10/qt
http://www.roushoil.com/5w-50.html
http://www.roushoil.com/5w-50.html
I'm finding it very hard to get good quality 5-50.
On that bases which way should I go, 10-50 or 0-40. Don't forget I'm in the UK so no excessive heat here.
It is reported by some that running a *w-40 oil in the engine will cause a loss of power from less than full valve lift due to leak-down of the hydraulic lifters. I recommend only running oil meeting the Ford specs.
jack at accufab proved it! :thumbsup :cheers:cheers
Castrol ...Ford WSS–M2C931–A .....
Anyone familiar with the difference between "A" and "B" specs? Not sure I want to deviate from the "B" as it is specified for our gals. At least not until the warranty period is up.
Incidently Mike, the Ford WSS-M2C931-A spec (API service "SL") oil was the original formulation and comes with a "black" cap on the bottle. The newer WSS-M2C931-B oil (API service "SM") has reduced amounts of “ZDDP” wear resistant additive which has been linked to high mileage converter fouling and comes with a gold colored cap