Mobil 1 seems to be the standard synthetic choice for most. Personally I'd stick to a good dino oil if that's what it came with. You're only driving about 12K a year, you'll trade off the truck long before you'll ever see any benefit to synthetic oil. I have a 2005 Toyota camry that's been fed Valvoline dino oil all it's life and it's got 270,000 miles on it now, still purrs like a kitten.
