I tried the search function and found nothing for this vehicle. It is a 2003 Dodge Ram with the 4.7 engine. The owners manual says to use 5w-30 and thats what I have used. It now has 7,000 miles and I want to switch to synthetic. Question is should I go 5w-30 or 10w-30 Mobil 1. Some people say the 5w is a better Mobil 1 than the 10w, some say its the other way around. Veh is used for mostly short trips in the hot Florida weather. Im confused!