Schaeffer Manufacturing Co. 9000CK4-006S SynShield OTR Plus Full Synthetic Diesel Engine Oil 5W-40, 1-Gallon Bottle

A friend inherited an ‘05 6.0 PSD and had no idea what maintenance had or had not been performed on it — a respected independent diesel shop later told us that the truck had not been well maintained. I started the engine and noticed it took a few more revolutions to get the engine to fire. I checked the oil and it was as black as the tires. Not knowing anything about the 6.0, I bought a non Motorcraft oil filter and a non synthetic 15W40 diesel oil. The engine continued taking more revolutions than I thought was normal to get it started. I read up on the 6.0 PSD and found that I definitely purchased the wrong filter and likely the wrong oil. I purchased a Motorcraft filter AND CAP, Schaeffer’s 5W40 full synthetic and Archoil Friction Modifier. Approximately 100 miles into the second oil change the 6.0 started in one half the time that it took with the other products. I’m still sold on changing the oil and filter every three thousand miles. Three thousand miles later, I was pleasantly surprised at how clean the used oil was. On the 6.0 PSD I would suggest Schaeffer’s 5W40, a Motorcraft filter AND CAP along with the Archoil Friction Modifier. I would also suggest using the Archoil diesel fuel additive. I know that this stuff is expensive, but it makes her 6.0 happy! This regimen, a thorough servicing and detail has turned this into a nice truck.

Best oil ever made

Truly in a league of its own. I did a ton of research before choosing this oil for the first oil change in my 6.7 Cummins. I've got to say that I am beyond thrilled with the results. I could immediately tell a dramatic improvement in the engine power, acceleration and responsiveness. I also noticed the engine noise is quieter now and there's no noticeable ticking noises either. The increased performance truly makes the truck even more fun to drive!

I’ve ran this for years and have never had any issues. Definitely worth the money.

My engine has never been cleaner thanks to Amazon and Shaffers! I’ve been running this oil for years with zero issues! Buy it today!!

A little expensive but oil is the life of your engine. Worth the extra money.

Great oil, it’s a little pricey, but works well! My truck does do well with it and my fuel efficiency has gone up. The only suggestion I would make for seller is to tape a seal around the cap. I was worried because a lot of people had issues with oil leaking out because of the seal. I did not have any issues with it leaking, but I only ordered one. I found it cheaper at a local shop.

Can’t recommend Schaeffer oil products more. Religiously use this oil in my personal truck (2017 F350 Powerstroke) as well as several other of their products at work.