pick one and stick with it. I will put my vote towards Mobil1 though. I always used it on my '98 since I bought it new and when I put the cam in at about 80k the lifter valley was clean and the lifters came out with no problems. No coking or residue. I use it in my truck.
'02 1500HD, 6.0L, magnacharger, 2000stall, custom magnaflow with electric cutout, E-fans, Nelson custom tune, Auburn LSD.
'79 L82 vette, Summit 355, Dart Pro1 heads, Comp 274 cam, Holley TBI, Built TH350 with 2500stall
'93 Blazer, full size 2dr 4x4, new project.....