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

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.

Best oil on the market it’s the only oil I’ve used in my medium and heavy duty trucks.

This is a good product, this price was better than what Schaeffer direct offered. To get better, my order would have to be a lot bigger. The convenience of delivery was helpful. At one time there was much less costly Chinese alternative but no longer available and it didnt have the ratings CK that this purchase offered.

Great fuel economy, incredible oil!

Very expensive,I am dissatisfied ,my motor is now louder than it was before, especially when cold.I just dont see me using and pay in extra in the future for this product

I’ve put 110k miles on my truck over the last three yrs and finally switched to Schaefer’s. She’s instantly running more smoothly than I remember before the wear and tear. Impressive stuff. Should’ve started using it BEFORE all those miles but this has definitely made a notable improvement.

For Hubbys stuff..

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.

Only Received 11 qts was in a bag inside a box , no case

The best oil money can buy. I use it in my 1999 dodge cummins diesel