The 5000 is if you drive regularly on the freeway for 20 miles or more, and you never hit traffic and you never dive in the city. So unles you do that 3000 is the best bet. As far as the oil type goes, if the manual says 5w20 use 5w20. I don´t car if the 5w30 is syntetic or not, 30 viscocity is 30 viscosity. That oil will not flow as well as the 5w20 through the passages and bearings.