I must concur with the choices of Mobil Delvac 1 and Amsoil. I use the 15w-40 Amsoil year round and like it alot. I've heard nothing but good things about 5w-30. But I wouldn't use it unless you are in a constantly colder climate.
The Delvac 1 may be your best bet though. 'Cause you can get it anywhere. Well, almost anywhere. Moreso than the Amsoil. Not to mention that it is a great oil.
\'99 2500 ISB QC SLT (No Leather!),4x4,5sp w/McLeod,4:10,BP8x11\'s,B-1,FMS,EZ,PE4200,LPG,H2O/CH4O,4\"exh.,Pac-Brake,OBA,more switches than you,Line-X,V-1,lts,siren,lic. plt. frm says \"<b><i>Diesel Fumes Make Me Horny!</i></b>\",and much more goofy stuff.
