If you need a oil additive then you need a new oil.

http://www.carbibles.com/additives.html

 

I have been using the 100% synthetic engine treatment. I figured 'an ounce of prevention...'; for an extra $10 what could it hurt. So far so good.

 

I have an '03 outside the VIN range and have 105,000 relatively pain free miles on it. The largest expense being a head gasket repair and the second largest being the intake water jacket gasket. Other than those its been nothing but normal maintance.

A out of the VIN range, properally maintained '03 is no worse that anyother DII.

 

My 03 is in the death vin range and like most say its sort of a crapshoot of whether you get a "good one" or not, good news is at least in the used marketplace its sort of a natural selection method of what trucks have made it so far, mine has probably 90,650 miles or so on it and I get 15psi HOT idle, my logic is if the truck lasts 40/50/60/70/80,000 miles on the stock pump, why wouldnt changing the stupid cover/oil pump gears produce the same results again? I think I could live with changing a front cover every 4-8 years man. If you have an 03 and you are skittish about the pump letting go, put on another one if you want to be proactive. If that is the main issue with an 03 THEN you can move on to the fact it does not have a cdl, now THAT sucks. You have to have the mentality that you can fix anything when you own one of these trucks. Its all nuts a bolts and all rovers have issues one way or another. Come to think of it, alot of the failures manifest as cracked/exploded oil pump gears due to the dowel misalignment, so spend 80 bucks on new gears and throw those in there for another 80k right? The solution sounds so simple instead of just passing on an otherwise cool truck.