Originally posted by Rara:
the clearances in Ford Duratecs, and modular V8s is not designed for 5w20, they are all designed for 5w30.

5w20 in those engines show a noticable increase in wear, and decrease in overall life on extensive Ford dyno testing.

5w20 is acceptable, but is absolutely only recommended for Ford engines in order to increase CAFE averages. 5w30 is significantly better for the overall health of the Duratec.

How much of an increase did Ford actually see by going to the 5w20? I'm assuming that increased wear is over a long term? My Lightning was fine with 5w20? Is Ford going to 'tighten' its specs to accomadate the 5w20?

Ryan Trollin!