I've never had a single problem with my motor. As long as the engine is maintained well...it'll run well. I use 10w-30 btw

 

I ran a lighter oil (10-30??) on my 2000 5.9 motor and did not like it, hard to explain but the motor felt different and did not give me the mental comfort level the 15/20-50 oils gave so I just stick with them. my wifes corolla calls for the 5-30 oil and I still run the 15-50 mobil1 in it. runs fine, same mileage and it is no quieter.

I'll be picking it up on Thursday and once I get it cleaned up, I'll post some better pics of it.