Hello everyone. New guy here with some new to me wheels. Its an 06 cvpi with 88K miles. It was a former police vehicle and had motorcraft 5-20 used in it its whole life. Heres my dilemma. Id like to run 5-30 in it, preferably M1 fully synthetic. The car will see more highway and interstate driving than city. Would this be ok to run a slightly thicker oil in it like a 5-30? I have two reasons Id like to run the 5-30 M1. Our wallmart is ALWAYS out of the 5-20 M1 synthetic. The car will see alot of high speeds, highway and interstate. Oh and one more thing, thank you for this great website. Ive been doing alot of reading here and enjoy it very much. Ive been an oil guy, if you could call it that for some years now and think I'll fit right in here.