My first service on all trucks and motorcycles install a K&N air filter and oil fillter. I usually buy oil filters for each vehicle by the case as know I will use them. I know I have five of my last six Harley Davidson Evo K&N oil filters waiting as well as at least two for the Shovelhead.  The dealer still services the "better half's" Twincam but they use K&N at our request.  Every truck or motorcycle gets serviced every 5,000 miles where we "wash and oil" the K&N air filters then put on the new oil filter and rill with appropriate oil. Both Dakota's always get Castrol 20-50 standard oil, the 97 Ram gets Royal Purple 20-50. the Shovelhead and Evo get Royal Purple full synthetic motorcylce oil formulated for air cooled V-Twins and the Twincam gets Harley-Davidson (Amsoil in a H-D jug) full synthetic.

    The 91 Dakota I regret selling at 520,000 miles and if able to go back in time would ralk myself out of selling. It had the K&N air filter in it that I installed at its first service when sold. My 93 Dakota has the original air filter installed at first service and is at 428,000 miles. The air filter on the 97 Ram (it has had an overheating problem since about year 2000) and when doing the 5000,000 mile service noticed the air filter was beginning to show some small cracks in the rubber seal so called K&N to ask if it was o.k. (planned to go by another if they said no) and they asked me the year model of truck and engine size then three days later a new one arrived at no charge. They didn't ask for photos, old filter returned they just expedited me another filter out that is holding up well and truck is showing 450,000 miles. Our 2007 Hemi has K&Ns and soon as my new truck requires new air filter hope to put a K&N cold air filtration system on it. Use K&N filters, good synthetic oil, run premium gasoline, service every 5,000 miles and use good syntheric oil (I like Royal Purple) and grease (Lucas) they will last a half million miles easy.