Shell Roletta T (regular version in the '91 and synthetic in the '97 TDI) (and Walmart is selling the Shell synthetic stuff at like $12.98 for the gal jug... good price especially compared to Mobile 1!)
Appreciate the info.
When I was a mechanic 35 years ago, engines were good for about 100,000 before overhaul, and I attribute the longer life of newer motors to better oils.