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

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

Its the best. Love Schaeffers oil

AS A TECH I HAVE SEEN WHAT THIS OIL CAN DO TO A ENGINE AND I WILL NOT USE THIS OIL IN ANYTHING !

This oil company is the best in the biz!

Would give this 10 stars if I could. Oil makes my Cummins a lot more quiter. Doesnt shiver like a chiwawa anymore and oil change intervals now at 7k miles.

Case leaking oil when it arrived

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.

After 2 hours run time its still clean.

I like that oil very much,(addicted to it) tried this oil in different cars, works perfect Ram 3500 Cummins 6.7, towing Goosneck, got 20000 miles of oil change. Mersedes ML350 Bluetec 15000 of oil changes, analyzing oil after 30 to 52 % life left.

I use it for my 2005 6.0l powerstroke f350. Amazing product, the engine fires right up cold starts hot starts does not matter. My new go to for oil. I bit more money but I dont have to run a Lucas additive anymore.