I stand corrected, 25,000 miles, 700 hours or 1 year. If your driving 96 miles a day five days a week you will get 25,000 miles a year. Or you idle/drive your car for 2.7 hours a day. I really have never been that guy.
Mobil, Castrol and pennzoil 0w40 could all easily do a 10k 1 year in most vehicles.
Wonder how amsoil would do pulling 20,000 lbs in a ram 5.9 full on max towing in foothills and mountains 3000 rpms, dusty roads, negative degree starts, short trips, long trips, idling in the fields. Maybe 8k a year of the most hellish miles you can imagine.
Amsoil oil change $140, regular Dino 15w40 $50. I'm sorry, but I'm dumping the oil three times a year and getting the crap out before the filter goes into bypass. UOA's have shown all major brand oils to be fantastic when changed within their limits. Highway commuters in non severe service would do better with amsoil. If you pay someone else 20-30 bucks to do your changes amsoil works also. your probably burning at least 3 quarts through the crappy Pcv valve in a ram in 25k miles. Fiat solved the pcv valve problem for the 6.4? hum... we'll see, maybe.
I pulled my intake and heads on my 5.7 at 80k and found huge amounts of oil caked on to piston heads, especially the mds cylinders. I degreased my intake manifold for days in a large tub. Luckily no direct injection so intake valves were pretty clean, but eventually the oil build up on pistons would cause pre ignition/ retarding. The stock cam,with that thin 5w20 was flawless.
Amsoil/redline is the best but may or may not be worth it depending on truck use. I could never not get under my truck and turn the wrenches for a year, I would feel like a bad owner.