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Customer Ratings & Reviews

Signature Series Max-Duty Synthetic Diesel Oil 5W-40

Product code : DEOQT-EA

4.9 star rating Read 947 reviews

Customer Rating

4.9

89% would recommend

  • 5 902
  • 4 34
  • 3 3
  • 2 3
  • 1 5

Signature Series Max-Duty Synthetic Diesel Oil 5W-40

4.9 star rating Based on 947 reviews
  • 5 star rating
    Diesel oil
    By  DAVID,  a  Verified Buyer  on  October 10, 2022
    Awesome oil
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Doing its thing for years...
    By  JEFF,  a  Verified Buyer  from  Turtletown, TN  on  October 09, 2022
    Been a long time user and most recently in a 2015 Ram eco diesel. About 107,000 miles on it and has never leaked a drop, used a drop nor had any oil\engine related issues. Same with prior 1-ton Dodge dually and Ford F350 diesels. Shipping has always been quick and picking up from Orlando, FL on visits I've found the order ready and the folks helpful.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Awesome
    By  RADU,  a  Verified Buyer  from  Portland Oregon   on  October 08, 2022
    Very good quality, I use on my 21 silverado duramax, and I love it, I recommend this product
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Signature oil
    By  STEVE,  a  Verified Buyer  from  Vernon Ct.  on  October 05, 2022
    One and done per year. I like their products across the board.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best oil for my Duramax diesel
    By  LUIS,  a  Verified Buyer  on  October 05, 2022
    I loved, this is the best synthetic oil for my Duramax Diesel engine
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Definitely the best oil I’ve ever used
    By  TRAMPUS,  a  Verified Buyer  from  Texas   on  October 04, 2022
    From cat equipment to my personal duramax this is the only oil I will ever use again! Thank you Amsoil for making a fantastic dependable product! I will be a customer for life
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel Oil the only way to go!
    By  RICK,  a  Verified Buyer  from  Kansas  on  October 02, 2022
    I have used Amsoil for years , in my opinion there is none better. Never find any other fluids in my vehicles,
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  • 5 star rating
    RDM
    By  ROB,  a  Verified Buyer  on  October 01, 2022
    Excellent oil,,, we only use the best in our trucks.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great oil will continue to buy
    By  JOSH,  a  Verified Buyer  from  Farrwest  on  September 26, 2022
    Your oil is better then others that I’ve used so I will continue to use
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Reliable Products
    By  JESSIE,  a  Verified Buyer  on  September 25, 2022
    AMSOIL has been a part of my engine maintenance regimen for many, many years and has always out performed the competition.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel oil
    By  MARTIN,  a  Verified Buyer  on  September 25, 2022
    Great so far!!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel oil
    By  NICK,  a  Verified Buyer  on  September 21, 2022
    Quick delivery can’t beat Amsoil
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Synthetic Diesel Oil
    By  ALBERT,  a  Verified Buyer  from  Cold Lake, AB  on  September 21, 2022
    By using this type of engine oil I found that my engine runs cooler, Fuel efficiency has also changed. Engine itself being diesel with this oil the motor runs quieter.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    For my 2019 F250
    By  PAUL,  a  Verified Buyer  from  Flowery Branch, Ga  on  September 13, 2022
    I tow approx 10k lbs pretty consistently (40-50% of my miles) and have always used Amsoil for the extended drain interval. With about 40k mi on my truck and approx 15k miles on my oil, I decided to send my oil to blackstone for analysis. I’ll spare you all of the details but will tell you that they noted that I could safely extend my oil change interval out approx 10k more miles, taking the oil life to 25k miles. While they may be true, I just stick with annual oil changes to keep it simple.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel oil
    By  Chad,  a  Verified Buyer  from  Missouri  on  September 03, 2022
    Best diesel oil yet. Engine idles smoother and feels like acceleration is faster. Cold weather starts are no problem. Highly recommend.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Superior product!
    By  Scott,  a  Verified Buyer  from  Ellerslie  on  August 28, 2022
    Been using Amsoil for many years! Best quality product on the market for synthetic oil.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Solid
    By  ANTHONY,  a  Verified Buyer  from  maine  on  August 28, 2022
    I use the signature series diesel oil in my powerstroke , and i use this oil in our f150 - great oil results in both.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Amsoil Diesel Oil
    By  RICK,  a  Verified Buyer  from  California   on  August 26, 2022
    Have never used any other oil in my Duramax and will never. Amsoil makes having an account and ordering online super easy. Use in our Triton V10 motor home, GMC Denali, Jeep Wrangler, ‘05 Duramax, Honda Generator, stihl blower etc. lifer!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Holds up well to desert heat
    By  ERIC,  a  Verified Buyer  from  Southern Arizona  on  August 26, 2022
    Fantastic oil, been using it for years.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great product
    By  PATRICK,  a  Verified Buyer  from  Texas   on  August 24, 2022
    12,000 miles on last oil change Amsoil oil still looked great
    Bottom Line
    Yes, I would recommend this to a friend.
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