Preparing to buy a 2001 with 164K miles. Truck's in great shape mechanically with one small body ding where the bumper meets the fender. Turned a trailer a little to short. Anyway, I'm getting it for less than trade-in. With that many miles, should I look at a high mileage oil like Maxlife in a 5W-20 or 5W-30. I a little squeamish about a 20-weight although there are plenty of UOAs that help relieve some of the anxiety. You've got o understand that I'm about to hold a wake for my trusty 1988 Ford F150 with the 5.0 that finally played out on me with 467,000 miles on the odometer. That truck was fed a steady diet of Castrol GTX 20W-50.