Mr. Kennedy's right - use a motor oil formulated for diesels. There are compelling reasons to do so.
I use Amsoil's 15W-40 Synthetic Heavy Duty Diesel and Marine Motor Oil. I have used different Amsoil motor oils in all the different vehicles I've had with excelent results.
2004 CrewCab Longbed, D-max/Allison, Line-X bedliner, Go-Rhino wheel-wheel bars, UNI air filter, Kennedy Mega Fuel Filter. Edge Juice & Attitude coming soon. I need upgraded exhaust, but my wife is gonna B!@#$ about the juice already.