x3, oil is mostly preference. but if your looking to venture, delo is neat because its cheap, but it also depends on your driving habits, style, mileage, and what your truck responds to. for example, if you drive a ton, or lay on the throttle like some of us do, i would highly recommend a synthetic. if you use your truck for nothing special and are consistant on maintenance delo or rotella would be just fine.
2002 crew cab LB7/allison 1000 sleeper in progress.
K&N intake, FASS 150gph, BD wastegate, banks monster exhaust, Flowmaster DP, DRP horn, Built trans, t-case rub kit, custom sleeves/ trac bars, autometer boost & pyrometer guages, SSBC front brakes, Amsoil front to back.
Injectors and EFI Live By Wade Boyd @ Diesel Day Dreams....Ill get 600rwhp with an IHI or blow up trying....maybe ill just get a turbo.