Before owning my CSVT I had (3) Buicks that I bought used, an 87 GN, 89 LeSabre T-type and a 93 Park Avenue Ultra. They all had 80K+ miles on them and I switched over to Mobil 1 w/o any problems
During the winter monthes you might want to get 0w30 Mobil 1 to aid in start up, just to help things get warmed up on those cold winter mornings
