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AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil

Product code : DMEQT-EA

4.9 star rating Read 1,338 reviews

Customer Rating

4.9

92% would recommend

  • 5 1282
  • 4 41
  • 3 6
  • 2 3
  • 1 6

AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil

4.9 star rating Based on 1,338 reviews
  • 5 star rating
    Best Product-Best customer service
    By  JUSTIN,  a  Verified Buyer  from  Belledonte,pa  on  March 07, 2025
    Ive been using amsoil almost 30 years and has certainly proven to me that it is everything they say it is..I certainly recomend it. Ive just started ordering directly through amsoil for the 25% discounted price and one of my orders had 2 quarts damaged, took a pic and emailed it and within hours they responded and sent new ones immediately. Couldnt be happier with service! ⭐️⭐️⭐️⭐️⭐️💯
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    2016titan xd
    By  JONAN,  a  Verified Buyer  on  March 04, 2025
    The best
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great Lubrication
    By  FRED,  a  Verified Buyer  from  Holyoke, CO.  on  March 03, 2025
    I have continually used the signature series 15w-40 from the first oil change when the truck was new. My 2014 Ram 3500 still runs strong. I always have my oil analyzed at every change. After 229k miles that analysis is still in the green. Had a couple minor oil leaks and a bad turbo actuator and that is all I have had to repair. Thanks Amsoil for your superior products.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent oil for my 2015 F350
    By  WADE,  a  Verified Buyer  from  Texas  on  March 03, 2025
    Been using this oil for a few years now and I really like it. It has long life and works well with the Amsoil filter.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    6.7 Powerstroke
    By  ROBERT,  a  Verified Buyer  from  St. Augustine Florida  on  March 02, 2025
    I use Amsoil 5W 40 Signature Series in my 2016 F350 with the 6.7 Powerstroke. I have reviewed several different brands and Amsoil is always in the top. It is also very competitively priced compared to Motorcraft Full Synthetic 5W-40. I appreciate the fact I can have it delivered right to my door and not have to go to the dealership and hope they have Synthetic in stock.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best
    By  JOHN,  a  Verified Buyer  from  Okeechobee Florida   on  March 02, 2025
    Great product I wouldn’t use any other motor oil in my vehicles
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best oil I've ever ran
    By  HAAKON,  a  Verified Buyer  on  February 24, 2025
    Awesome stuff. Changed the feel and sound of my 6.0. Extremely happy with this oil.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 3 star rating
    Great but Pricing
    By  DAVID,  a  Verified Buyer  from  Upstate SC  on  February 22, 2025
    I love their product that's highly recommended by Ram trucks but it costs ! Wish it was competitive with Rotella, Valvoline, and others.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great product. Only oil I will use in the Duramax.
    By  TIMOTHY,  a  Verified Buyer  from  Arizona  on  February 21, 2025
    I love this product and use only Amsoil products in my vehicles. It is the best product on the market. It out performs all other available synthetic products on the market.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Performance and Durability
    By  PETER,  a  Verified Buyer  from  NJ  on  February 18, 2025
    Excellent product for its wear protection. Zero oil consumption. No worries when you occasionaly go past recommended oil change intervals. Oil temperatures stay lower under higher loads. 2.5 gallon container size is an added plus.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Amazing stuff
    By  DEREK,  a  Verified Buyer  on  February 17, 2025
    Use to use other motor oil on my Duramax and it would burn roughly a quart every 4k miles. Truck does not burn this stuff and oil still looks brand new after 3k miles. Highly impressed by it and recommend it.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil works good
    By  VICTOR,  a  Verified Buyer  from  NH  on  February 17, 2025
    very good quilty oil will be buying again
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    best oil for longevity
    By  MARK,  a  Verified Buyer  from  florida  on  February 15, 2025
    In my 2004 dodge diesel, which was purchased new, I have used Amsoil oil and filters since it's first oil change, about 490,000 miles ago, with no engine repairs required. I change the oil and filter once a year or about 25,000 miles. Highly recommend. I use Amsoil products in everything that needs oil, Tahoe, 4-wheeler, lawnmower, outboard motor, etc.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    AMAZING customer service!!
    By  ROBERT,  a  Verified Buyer  from  Texas  on  February 14, 2025
    My Amsoil dealer ALWAYS gets my products to me way faster than expected!! The brand speaks for itself, so having the added excellent service keeps me coming back everytime!!!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Don’t go cheap on your diesel oil?
    By  GREGORY,  a  Verified Buyer  from  Washington State   on  February 01, 2025
    Put the best stuff you can afford in your diesel. Amsoil checks all the boxes for me and helps keep my diesel running like new. I change my oil every 5000k miles. For the cost it’s cheap insurance for my motor.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Fast shipping, and great a product
    By  ANDREW,  a  Verified Buyer  on  February 01, 2025
    Could not recommend more
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Would recomment
    By  BLAIR,  a  Verified Buyer  from  Alberta  on  January 27, 2025
    One my 3rd oil change on my new duramax now. I don’t do the recommended 25000km I change at 10000km I idle a lot more then most so it gives me peace of mind
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Fine product
    By  PG,  a  Verified Buyer  from  San Antonio  on  January 26, 2025
    Purchased my Ram 2500 truck in 2015 and since then, I've used AMSOIL Signature exclusively since 2018. The truck gets decent mileage whether driving "normally" or towing my travel trailers. I've not experienced any engine related issues at all, knock on wood.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil Change
    By  WAYNE,  a  Verified Buyer  from  Snyder Oklahoma  on  January 24, 2025
    I've been a devote user of Amsoil for my oil changes and it has always kept me going.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Pickup truck oil
    By  JEFF,  a  Verified Buyer  from  West Central Illinois  on  January 21, 2025
    I think the AMSOIL is the best oil on the market. The shipping is very fast. I usually receive the product the next day.
    Bottom Line
    Yes, I would recommend this to a friend.
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