Schaeffer Manufacturing Co. 0700CK4-012 SynShield Durability Advantage 15W-40 Diesel Engine Oil, 12-Quart Bottle (Pack of 12)

Excellent oil!! Runs well on the 2003 6.0 powerstroke.

I can’t say enough about this Diesel engine oil. Best stuff on the market.

This stuff is in fact.. the cats MEOW!! I would only recommend this formula for cooler climates before running it myself, but it in fact holds its own in severe heat as well! It holds slightly more oil pressure than Rotella 10W-40 at the same temperature! I’m pleased! I’m running this in everything I own now!

Excellent quality oil. I use this in an old 3800 GM v6 and it works quite well. Although not fully synthetic, if you do your research, this is much better than even full synthetic Castrol. Pour point, viscosity index, and flashpoint are very impressive. Moly enhancement really works, probably better than Royal Purple which is another moly enhanced oil.

Typically the oil in my diesel turns black shortly after a oil change. (this is normal) The Schrieffer oil is not doing that as quickly. Very happy with the oil. I will review it again at 4000 miles during the my next oil change.

This is the best oil by far.. Garantied to notice a difference..

Top of the line oil no doubt but, it’s advertised as 5 gallons but only contained 4.5 gallons. Where are the other 2qts I paid for?

I tried this due to not being able to find Rottela T5 in the stores. For me this will be a permanent switch. My 6.0 starts easier runs quieter and seems to get a little better fuel milage.

Good oil at a great price, well worth the investment as I plan on driving the tires off this thing. I was previously running Castrol Full Syn and switch. My idle oil pressure is now 10 PSI higher. I tested this on a brand new oil pump and used Castrol after replacement. Used Sheaffer on the next oil change and I am happy to see the oil pressure running hire..

Great oil, can go way longer now on oil changes. Saves money on maintance. And motor runs so smooth.