Arrr matey (sorry couldnt resist) this is the first time i have had something to say so herrr goes . when i got my 98. 5 the oil was real dirty so thought i would get an amsoil (had fleetgard on it) the amsoil website had a chart of top tier oil filters and they were #1,however they showed #2 as mobile 1 at 10. 99 at autozone i started using them. to make a long story short after 3 oil changes my oil looks like new after 3500-4000 miles the truck now has 152k and i wont quit using them. so paul if you want your ride to last take care of it. they sell me a case of filters for 8. 99 ea . good luck dirk