Aight, just got a new 06 Nissan Titan. The truck has 51 whole miles on it and power to burn! My question is thus: The manual says 5w-30 is preferred all the time BUT that 10w-30 and 10w-40 can be used in temps over 0 degrees. This engine is hard on oil supposedly (chain driven DOHC) and has a 6.5 qt sump. Should I use a 5w or a 10w? Should I use a syn or a dino? Which brand? Ahhhhh....decisions decisions. Thanks guys!