I thought I'd pass along my latest oil report, using an expensive synthetic to see how it held up through the winter.
Oil is Mobil Delvac 1; 5W-40 CI-4 rated, filter is Fleetguard StrataPore LF3894. Miles on oil, 8,647, in service 10-17-03, sample drawn on 4-28-04 with 102,879 miles on engine. I did change the filter only in January, and added 1 quart of make-up oil at that time.

Wear metals in ppm:
Aluminum 4
Chromium 2
Iron 19
Copper 1
Lead 2
Tin 0

Silicon (dirt) 4
Sodium (road salt possibly) 2

Additives,
detergent/dispersant:
Boron 49
Calcium 2517
Magnesium 425

anti-wear:
Phosphorus 1181
Zinc 1367

Total Base Number 7.4

SUS Viscosity@210F 75.6 (40 grade)
FLashpoint 455F
Fuel <0.5%
Antifreeze 0
Water 0
Insolubles (soot) 0.5%

Proves once again, the Cummins is easy on oil. I used the block heater twice this past winter, so most of the start-ups were cold, which didn't affect engine wear. The truck plowed alot of snow this winter as well, and did see it's fair share of short trip driving. This fill of oil is still in the crankcase, and I'll probably run it until fall. I paid about $23 a gallon for this stuff, but notice Mobil 1 now sells the same stuff as "Truck and SUV 5W-40", and it's available at Wal-mart for $4.77 per quart.

 

Looks real nice. Delvac 1 has a small amount of Sodium in it right out of the bottle, no road salt in your oil.

 

Thanks for the info on the sodium.