Customer Ratings & Reviews

I've been using Amsoil lubricants for decades. I'm loyal to the brand. I've been with Amsoil through the good times, and one of their bad times (back in the eighties). I've run Amsoil in motorcycles, cars, trucks, boats, high-performance engines, and factory daily drivers. I have extensive experience in engine machining/building, and I've seen, first hand, how Amsoil provides performance and durability to engines that push their design limits. Recently I bought a 2017 F250 with the PowerStroke diesel, and I got to reading about the particulate filters, and how oils not approved by Ford could cause premature clogging of the DPF, and possibly void the manufacturers warranty. Oils manufactured to the CK-4 spec initially resulted in premature wear in 2017 PowerStroke engines, so Ford released their own specification, WSS-M2C171-F1, and instructed owners to run CJ-4 oils until approved CK-4's were available. Since then several products have been approved by Ford for use in PowerStrokes, but concerned about the performance of the available CK-4 oils, and curious about how Amsoil's Signature Series Max-Duty Diesel Engine Oil compared to them, I submitted a couple of samples to the guy who runs the 540 RAT Blog for testing. The Amsoil product tested superior to all others tested to date, beat only by another of Amsoil's own CI-4 spec diesel engine oil. I wasn't surprised by that, based on my experience, but I was surprised to see a conventional CK-4 oil approved by Ford that also meets WSS-M2C171-F1, performed as well as Amsoil's Sig Series Max-Duty, and costs about half what Amsoil's product does. I would love for Amsoil to explain why their product is still superior to that competing product, even though they performed so similarly in 540 Rat's test. At thirteen quarts, half the price is quite a savings. Is it really worth the price?

Great oil for my 2500 Jd

This product is great. I have ran this product the last 15,000 miles. My trucks starts smooth after sitting for a week in the cold weather of northern NM. Never misses a beat either. Would recommend to any diesel owner out there.

Since 2010 I've been using Amsoil fluids and filters in my Dodge Ram 2500 Cummins Diesel and as a result, have had no engine or transmission failures. The diesel engine oil & filter are both 25,000 mile change frequency; Amsoil does cost more, but you'll save money in the long run with zero failures and extended periods between scheduled maintenance. I also ran Amsoil transmission fluid in the same truck for 70,000+ miles with no slippage, and always witness iyuyreliable, positively locked shifts.

I've used this product as well as many other amsoil products in many trucks and pieces of equipment and they are superior to any other on the market. Much smoother running with lower temps and increased mileage.

Feels like my trtuck runs a lot smoother

I have used AMSOIL for over 30 years great stuff!

Duramax seams to like it, oil samples great @ 10000km, filter change and re sample @ 20000km!

Love using the best protection available for my Chevy 6.6 that I work hard everyday and with 123,000 not a single hiccup.

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I have used amsoil for years in my 6.7 cummins diesel and it has never failed to deliver . I recently swithed to the new 6x signature 5W-40 and I noticed that my oil pressure went up one pound and my fuel mileage went up one mile per hour also . Now to some this may not be a big deal but it adds up over time and that it is giving me better pressure at the same time only goes toward helping to further protect my engine. with the increased wear protection quality and potential I look forward to many more years of faithful performance from amsoil oil just like this .

Only use the truck to tow keeps oil temp down

The oil in my 199 F-250 SD with 7.3 diesel, bought new, use to get its oil changed every 3-5K miles for the first 6 oil changes. Then the switch was made to Amsoil Synthetic, with Amsoil oil filter. The oil still looks new after the first 3-4K miles and is changed every 10K miles. Although I have had no problem with this vehicle related to lubrication, the vehicle may be considered low mileage with 262,000 miles and o8il consumption has been greatly decreased. Love this oil.

I have used this oil in my Silverado Duramax in cold weather and it helps with cold starts and driveability during long warm-up time. The engine gets lubrication almost immediately upon startup and sounds like it is running on a summer day. Amsoil is the best!

Before using this product in a 2015 Silverado 2500 I had consumption of standard oil. Truck was using 1 quart of oil per 5000 miles. After switching to this product I have not experienced any consumption.

This is a high mileage truck 350,000 km it starts great in cold weather and a faster clean start

I have used this since the truck was new. 110,000 miles and it is running like new. During the recent cold weather, it started right away and oil pressure was At recommended level. Great protection!

2000 F250 7.3L TURBO!

I bought a 2001 F250 with 70,000 miles on it. After a couple of trips to a local quick oil change every 5000 miles at a cost of 150.00 I decided to try Amsoil diesel oil and am very glad I did .I use Amsoil diesel oil and filter I have extended the oil changes to yearly this by itself is a substantial cost savings the truck runs great and averages 16 mpg. It now has almost 250,000 miles on it and counting

Engine oil, Quality