Use the manufacture recommended weight and switch to a High Mileage oil.
5w30
About 4500 miles for car/truck over 150k
I recommend a high mileage oil such as Pennzoil High Mileage in the weight the manufacture of the vehicle recommends.
You should change engine oil in car or truck every 5,000 miles.
5w30
SAE 10w30 any major brand. If you have over 100,000 miles on this truck I recommend a High Mileage blend.
I would say if you keep the truck serviced regularly, change oil and all filters etc, you can expect at least 100000 miles before any major problems
You should change your oil in your new truck every three thousand miles at least. You should check your oil once in a while. If its a new truck check oil every month.
Use 10W30 and do not use 10W40 or straight 30W.
mobil 1 snytetic best oil study prove it
every 3000 miles
I would first change the pcv valve.Its cheap[ and would cause oil to leak in alot of places because of crank case pressure.