165K here...mostly highway miles.
I only run Synthetic oil...usually moble one.
Trans, transfer case, diffs have Royal Purple.
Every 50k miles I do a complete fluid flush. Engine, trans, transfer case, diffs.
I had that "crank position sensor " problem and replaced that
Chevy replaced the gas tank after many problems the first year...it wouldnt fill.
I have replaced one of the Catalytic converters, the brakes, tires, etc...
It does burn one quart of oil between oil changes....but has done that since new.
It seems like I have to replace the serpentine belt every 3 months or so because it squeels.