oil grade

[nmu98]

I am not an oil guru, but i say hell no. If you use 5w30 or 10w30, My guess is that only in really cold starting could you wear anything more than normal....

You are upping the weight of the oil when its hot by going to the 40. These new engines are built with very tight tollerances and designed for a specific oil. most Fords now want 5w20 and caution the use of 5w30.