Schaeffer Manufacturing 0700Ck4-006S Synshield Durability Advantage Diesel Engine Oil 15W-40, 1 Gallon Bottle

Okay, this is a long review, but hopefully will be worth reading. I’m not one to instantly believe a lot of hype that I read in product reviews. Rather, I try to gather as much information as possible from different sources and from both the positive feedback, as well as the negative. That said, I try to always be absolutely honest in my reviews in order to give people my personal opinion of a product’s performance, quality and cost-benefit value. Many of the reviews I have read on this oil stated there was a noticeable decrease in the diesel tick/rattle when reviewers started using this product. There were some that claimed an increase in fuel mileage, as well. These reviews were not limited to just one engine manufacturer, but included Cummins, Power Stroke, Duramax, TDI and others. I’ve always tried to use higher-end, quality products for my truck. While cost is a factor for me, I do know that often a few extra dollars spent up front can equate to money saved in the long term. Yesterday, my Schaffer’s 15W-40 order arrived and I changed the oil and filter (PPE extra capacity filter) in my 2002 Duramax/Allison 3500 4WD dually truck which I purchased new and now has 145K miles on it. I normally try to use a “quality oil”, such as Amsoil, Rotella, etc., however I’ve never used Schaffer’s products before. After reading the reviews on their products, I decided to give their oil a try. As I added the new oil, I was a bit stunned by the color of the oil. It is considerably darker than any other brand I’ve ever used. I’m assuming that’s a good thing. After all, Schaffer’s is purported to be a top-shelf product. When I was finished with everything, I drove about a mile, or so around my neighborhood to get the oil level to stabilize so I could get an accurate oil level reading. Did I notice anything different in that short little drive? Well, I thought I did, but I also thought that maybe I just wanted to notice something different. 😉 A few hours later, my wife and I took my truck to church which is about a 20 mile round trip. I kept the stereo off and just listened. WOW!!! My Duramax has NEVER been this quiet!!! Even when it was brand new. Whether at idle, or when I would accelerate hard, there was a very, very noticeable reduction/elimination in the tick noise I had always heard since the truck was new! The Ticking is virtually gone!!! Honestly, I’m actually quite stunned! Also, when the engine was running at its normal operating temperature, I noticed an approximately 5psi increase in oil pressure at idle. My wife agreed completely that the engine noise was noticeably much quieter than before. She isn’t one to notice subtle changes in engine sounds, but she did notice a big change in the engine noise, yesterday. My honest, final evaluation is the this; I’m truly, truly impressed! This is perhaps the single, most significant, simple and relatively inexpensive upgrade I’ve made to hopefully increase my engine’s longevity. Time will tell whether my fuel efficiency is positively affected, but my common sense tells me that it would most likely have to be. Should I find any significant improvement in mileage, or any other changes, either good, or bad, I’ll certainly provide an update. If you want to use what I believe to be an extraordinary product, give Schaffer’s a try. I can’t imagine you’ll be disappointed. I highly, highly recommend them!!! 😀

Run this product in my 2001 Ford power stroke with a 7.3l , 220 on the clock and it started to run not as smooth as it use to . Understandable with the miles. Frend of mine ask me if I would try it. I said yeah sure until I seen the difference in price. So I was like ahhh no that's ok ...he laughed and said I have a couple of gallons, try it for free and if you don't like how smooth your engine will run then you don't have to pay me for the oil ...I said ok I'll do that. All I can say is that it is well worth the price . I was amazed at how much smoother and cleaner sounding my engine was running if that makes sense. Idles so smooth and starts easier. Been in my truck for about 2000 miles now and I swear it keeps getting better the more I drive it . The turbo even sounds better , definitely recommend running on an older diesel engine. Not sure about newer diesels because I don't own one but I'm sure it can only be a great product for new engines as well

Been running this for about 700 miles and its great. The engine runs quieter and gets around 2 more mpg.

I really trust this lubricant. I have used it for a number of years in my tractors and truck - machines that range in age from 2016 to 1950. It truly has reduced wear and promoted good fuel efficiency.

Owning a Diesel engine, and researching toxic of oil for the engine, I settled on this product. The “oil geek” YT channel teachings, Is one venues of wisdom I use on ail related concerns. This has a cleanser trait most others oils do NOT. It's one of the better products HGH quality for our Diesel engines. I HIGHLY suggest change your Diesel engine oils & filter, 4K Miles. It's expensive yet the thing will last 500K miles or MORE, if you maintain it right. Diesel engines create SOOT and so the manuals say 10K miles, NO FLIPPIN way!! 4K Miles MAX. Unless you put in an oil bypass filter setup. Then double it. All example I seen of diesels lasting 500K-900K Miles were #1 secret, Change oil / filter Ofter!!!!