I just thought i would give my opinon on oil. there is two very important thing about oil. the first thing is CHANGE IT!!! the next thing is use DA oil. now i know all of you have not heard of it because it is the best kept secret in the oil industry. it is made by a company in Indiana it is made for all diesels on and off road. i worked at Cat for 5 years and it was the best oil ive ever seen. the give you FREE oil sampling also. i live on a 3000 acre farm and use it in all of my tractors and trucks. it is made as a long drain oil up to 70,000 miles!!! that is on the far side but it is possible. you take samples every 4000 miles or 150 hours and send them in they send you a report in about a week telling you the results. if there is a problem they call you and tell you to shut it down. as far as using it in your truck my dad runs it in his 95 dodge wich has 395,000 on it an he changes it every 15,000 his oil still is clean to this day. if any one is interrested let me know and i will get you some info. if you dont belive me ask your Shell ,mobile. or any other oil rep. and asy him if his oil is better than DA OIL!! i bet he lower his head and says no