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AMSOIL Signature Series 5W-40 100% Synthetic Max-Duty Diesel Oil

Product code : DEOQT-EA

4.9 star rating Read 1,130 reviews

Customer Rating

4.9

91% would recommend

  • 5 1077
  • 4 40
  • 3 4
  • 2 3
  • 1 6

AMSOIL Signature Series 5W-40 100% Synthetic Max-Duty Diesel Oil

4.9 star rating Based on 1,130 reviews
  • 5 star rating
    best on the market
    By  RODNEY,  a  Verified Buyer  on  February 21, 2024
    this is the best oil on the market
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Superior products
    By  RONALD,  a  Verified Buyer  from  Phippsburg, Colorado  on  February 19, 2024
    I have used Amsoil 5w/40 in my diesel F250 since 2008 I would not use anything else!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    number 1 oil
    By  luis,  a  Verified Buyer  from  FL  on  February 06, 2024
    great product
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Works great!
    By  JOSHUA,  a  Verified Buyer  from  Auburn Indiana   on  February 03, 2024
    Best quality oil on the market!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Product recommendations
    By  STEVEN,  a  Verified Buyer  from  Sequim  on  February 03, 2024
    Great product, price is worth the extended life and frequent changes.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent
    By  PHIL,  a  Verified Buyer  on  February 03, 2024
    I run this oil in my 2022 Duramax. This oil does not feel like it broke down at all after the 1 year change interval. I rubbed a little of the old oil between my fingers after the change, and it still felt new. I’ll keeping running it in my truck for years to come.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Converting Dodge Ram 2500 to Amsoil 100% Synthetic
    By  CHARLIE,  a  Verified Buyer  from  CA  on  January 30, 2024
    Just changed oil in my 2017 Dodge Ram 2500 to Amsoil 15W-40 100% Synthetic and what a difference in performance. Definitely my truck is a lot quieter and seems to have more torque. Getting ready to change my 2015 Lexus RX 350 to Amsoil 100% synthetic, these Amsoil products have really made a difference in the performance of my vehicles. A+
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Amsoil protects@
    By  Seventrumpets42 ,  a  Verified Buyer  from  Colorado   on  January 22, 2024
    I have only used Amsoil Signature 5-40 Diesel oil in my 2016 Ram since I purchased it with 722 miles. I do routine oil analysis at Blackstone Labs. I follow manufacturers recommended oil change interval of 10k. I just completed the 170k change and await the lab's analysis. I usually add 1/2 qt. between changes. Amsoil makes quality lubricants that can be surpassed!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great as always
    By  RICK,  a  Verified Buyer  on  January 21, 2024
    Shipped promptly, and is a great product. Unpaid spokes person.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best diesel oil
    By  kingsley,  a  Verified Buyer  from  AZ  on  January 15, 2024
    This is the best diesel oil to use in your diesel engine....my cummins works & sounds smoother
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil change
    By  BRANDON,  a  Verified Buyer  on  January 14, 2024
    Great product!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil
    By  TIM,  a  Verified Buyer  on  January 12, 2024
    Works great
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    A soul Products
    By  JAMES,  a  Verified Buyer  from  Lebanon Virginia   on  January 11, 2024
    I’ve purchased these products for my motorcycle and diesel truck. Love it. From oil to fuel additive and gear oils. Great Product
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 3 star rating
    Good product
    By  Ron,  a  Verified Buyer  from  TN  on  January 11, 2024
    Great product but the price is becoming ridiculous. I will probably be looking for an alternative soon.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Max protection 6X
    By  WILBURN,  a  Verified Buyer  from  Texas  on  January 09, 2024
    Excellent diesel oil with max protection
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    What a difference
    By  RICHARD,  a  Verified Buyer  from  Payson az  on  January 09, 2024
    Difference is unbelievably a huge upgrade in performance and protection, engine is running smoother and starts easier especially where I live it’s been 12 degrees at night even though I use my block heater I’ve noticed a huge difference in starting, before Amsoil I used only rotella t-6 full synthetic and I’ve always changed my oil every 5,000 miles, I’m a preventive maintenance person and I’ve noticed my last few oil changes the oil was really thin and it just didn’t sit well with me. I only drive about 10, 000 miles a year so it will be nice to only change it once a year.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Used since new, never had an issue
    By  CHAD,  a  Verified Buyer  from  MN  on  January 08, 2024
    I’ve used AMSOIL products on all our vehicles since new and have never had any issues. Would recommend to anyone
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Sig. Series 5W-40 100% SYN Max-Duty Diesel Oil
    By  RICK,  a  Verified Buyer  from  Florida  on  January 07, 2024
    after Break-in period of a rebuilt Manufactured 6.7L started using Max-Duty and can tell it's a high-quality oil, by sound, etc.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil
    By  JOHN,  a  Verified Buyer  on  January 06, 2024
    I ise amsoil. My truck is still running. It must be working ok.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    04 Duramax
    By  TERRY,  a  Verified Buyer  on  January 04, 2024
    Best oil money can buy!!
    Bottom Line
    Yes, I would recommend this to a friend.
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