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AMSOIL 5W-40 Heavy-Duty 100% Synthetic Diesel Oil
Product code : ADOQT-EA
- Delivers 4X more wear protection1
- Minimizes oil consumption
- Excels in extreme temperatures
- Helps keep trucks and equipment operating at peak performance
- Offers outstanding value
1Based on third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 using 10W-30 as worst-case representation
AMSOIL 5W-40 Heavy-Duty 100% Synthetic Diesel Oil
Developed to provide protection beyond conventional, synthetic-blend and other synthetic oils. AMSOIL synthetic technology delivers heavy-duty protection for diesel enthusiasts and those who depend on their trucks and equipment to make a living.
See the Product Data Bulletin for full details.
HEAVY-DUTY ENGINE PROTECTION
- Delivers 4X more wear protection1
- Helps maximize equipment life
- Helps reduce maintenance costs and downtime
1Based on third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 using 10W-30 as worst-case representation
Delivers More Wear Protection
Third-party testing shows Heavy-Duty Synthetic Diesel Oil delivers 4X more protection against wear than required by Detroit Diesel’s* standard.I
IBased on third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 using 10W-30 as worst-case representation. *All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use.
VISCOSITY CONTROL
- Resists oxidation and the thickening effects of soot contamination
- Retains viscosity after high-temperature service for added engine protection and increased fuel economy
- Provides up to 66 percent less oil consumption2
2Than required by the API CK-4 standard in the Caterpillar-1N oil consumption test
Reduces Oil Consumption
Heavy-Duty Synthetic Diesel Oil provides up to 66% less oil consumption.L
L Than required by the API CK-4 standard in the Caterpillar-1N oil consumption test.
EXCELS IN EXTREME TEMPERATURES
- Provides outstanding protection and performance in hot and cold temperature extremes
- Delivers improved heat and oxidation resistance compared to conventional diesel oils
- Flows dependably in cold temperatures for easier startup and improved engine protection
AMSOIL 5W-40 Heavy-Duty 100% Synthetic Diesel Oil
Data Bulletin
Data BulletinsLiterature Sample
Warranty
SDS
AMSOIL 5W-40 Heavy-Duty 100% Synthetic Diesel Oil
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star rating
Great product.By WILLIAM, a Verified Buyer from Pennsylvania on June 10, 2025Use AMSOIL in my Ram 3500. Really like this synthetic oil.Bottom LineYes, I would recommend this to a friend.Was this review helpful?
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Nothing but the bestBy JEFF, a Verified Buyer from Superior on June 08, 2025One always needs an extra tomato Things offBottom LineYes, I would recommend this to a friend.Was this review helpful?
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Great OilBy STEVEN, a Verified Buyer on June 07, 2025Run this oil in my 23 6.7 power stroke. Engine has 245k and oil analysis comes back with zero issues. Analysis says I can run longer but I usually change it around 7500 miles.Bottom LineYes, I would recommend this to a friend.Was this review helpful?
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Great Diesel OilBy JOSEPH, a Verified Buyer from Covington, Georgia on June 02, 2025We have a Ford F-250 & a Ford F-350 and if we were to take our trucks in for an oil change it's over $300 per vehicle. So we have been changing our own oil for the last three years now and with Amsoil we save a lot of money just ordering our oil and filters through Amsoil's website. We are very happy with their products.Bottom LineYes, I would recommend this to a friend.Was this review helpful?
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good oilBy DANNY, a Verified Buyer on June 01, 2025have been using this oil for 2 years on my '15 Ram Cummins. overall happy with oil . I sample my oils to extend intervals. I used Rotella T-6 prior and had better sample results. No concerning results, Rotella was just better.Bottom LineYes, I would recommend this to a friend.Was this review helpful?
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Great oil. Easy order processBy AARON, a Verified Buyer on May 29, 2025Always a great experience. Best oil around. Ram 2500 CummingsBottom LineYes, I would recommend this to a friend.Was this review helpful?
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Best you can buy!By ELLIOT, a Verified Buyer from OR on May 27, 2025What can I say? I’ve been using amsoil for 16 years. Great stuff.Bottom LineYes, I would recommend this to a friend.Was this review helpful?
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Great qualityBy RALPH, a Verified Buyer from Toronto on May 26, 2025I’ve been using AMSOIL synthetic lubricants for my pressure washer for over a year now, and I’m genuinely impressed with the performance and quality. The engine runs smoother, quieter, and feels more responsive, especially during long drives. I’ve noticed improved fuel efficiency and extended oil change intervals, which has saved me time and money. Their products are top-notch, and the customer service is exceptional—always prompt and knowledgeable. Whether it’s for my car or pressure washer, AMSOIL has become my go-to choice for reliable, high-performance lubrication. Highly recommend to anyone looking to keep their engine in peak condition!Bottom LineYes, I would recommend this to a friend.Was this review helpful?
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Engine quieter, Less smokeBy JOVAN, a Verified Buyer from Niles, IL on May 20, 2025This is the first time with Amsoil in my truck. From initial start up and driving i noticed a difference. First the engine is not as noisy and also I don't see as much smoke from tailpipe. Great Product. Thanks to my representative. Always has the right answer for your products!Bottom LineYes, I would recommend this to a friend.Was this review helpful?
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OilBy STEVE, a Verified Buyer from S.Florida on May 15, 2025So far I haven’t had any issues with using this oil, it’s the only oil I use. I have a 2000 Ford Excursion with a 7.3 liter diesel engine! Has almost 300000 milesBottom LineYes, I would recommend this to a friend.Was this review helpful?
