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

This oil company is the best in the biz!

Swapped to schaeffers from Rotella 15w40 and noticed increased oil pressure, slightly better fuel economy, and a quite engine. I was quite impressed. Its really good oil, but... the downside is the price, I recommend going through a nearby sales rep as the prices are exponentially cheaper than buying from a 3rd party vendor such as Amazon, Napa, O Reillys etc.

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

I love the oil but am very disappointed in the condition it was received.

Amazing product I run it in everything!

Nice oil

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..

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.

I have a 2008 6.4 Powerstroke its some of the best oil that Ive ever used when I started using chafers Ive had the cleanest filters Ive had since Ive owned the truck I highly recommend this to anybody.

Travel between Texas and Wisconsin several times a year. This oil has out performed all others hands down. My 2013 F-350 is a happy machine. Mileage Increased also by a mile per gallon.