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

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.

So, I started using this product in my fleet since the Supreme 9000 5W-40 CJ-4 is not recommended for newer EGR/SCR equipped vehicles. Two things Ive noticed: 1. The oil stays cleaner much longer 2. The buses use much less DEF. Because this is made by Schaeffers, I trust that the durability will hold up and keep my equipment running for many miles.

Great fuel economy, incredible oil!

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

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.

The best oil money can buy!!

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.

Reproductor Muy Bueno pero noso responsables con la devolu cion de dinero

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

Not very impressed so far. The oil has 3000 miles on it and the 7.3 was filled slightly over the top line on the dipstick before leaving for a 300 mile trip. My truck is ridiculously maintained and has never burned oil in its 240,000 mile life. Pulled into camp, parked and all was good. Next morning it would not fire up! Checked the oil level and was a little below 3/4, added a gallon of delo and it fired up of course after getting oil up to proper levels. In case you dont know, low oil and your injectors wont fire with ford 6.0 and 7.3, awesome system as you wont ever ruin an engine due to low oil. Obviously I do have an issue possibly with a low pressure oil pump but the oil should not burn off like this. No signs, smoke or running problems indicating an issue on the drive. Im disappointed especially after reading all the reviews on the forums over the years and finally getting to try this oil. It ran just slightly better than my regular oil for a few months and then now it runs rough like the oil is old just over 3000 miles. Will not be buying again and am sticking to locally bought oil