Product Reviewed: Synthetic Heavy-Duty Diesel & Marine Motor Oil SAE 15W-40 (AME)
Current Rating: 4.91 out of 5 stars
Votes & Reviews: 316 vote(s) and 236 user reviews.
Reviewed by Michael: 
The ONLY oil i use in my 2002 F350 7.3 Powerstroke. I get 25,000 miles between oil changes!
Reviewed by Flint:
it's a good product but I don't like the gallon jug design. They're hard to pour.
Reviewed by Leslie:
Have used this oil in my Duramax since it finally broke in at 70,000, I now have 255,000 on it and every oil test came with 50% oil life after 10,000. I do a lot of short trips along with really long trips towing.
Reviewed by Corey:
Makes changes a snap in my duramax. The 2 1/2 gallon jug fills her to the top of the stick. Great product and easy to order too
Reviewed by Jeremy:
2004 dodge Cummins Great oil Truck runs awsome
Reviewed by Billy:
I have used amsoil in my 2003 dodge ram 3500 the oil, performs very well has always checked good with an oil analysis 222,000 miles without ant oil related problems towing horse trailers and now a 36ft 5th wheel
Reviewed by Yaremchuk:
Very good quality.
Reviewed by
Kenneth:
Boatload of additive for Excellent TBN analysis between extended oil changes.
Reviewed by Brandon:
Great oil. Love it so far!!
Reviewed by Andrew:
I use this in my 98 Dodge Ram 2500HD with the 5.9L Cummins 24v engine. It's been great to the engine.
Reviewed by Mike:
This motor oil is used in my F250 work truck. I've been using it for around 130,000 miles
Reviewed by Dennis:
Great lube. Have used in gas and diesel motorhomes
Reviewed by Joey:
Great product. I have used this oil in this truck for 20 years. I find it runs as good as the day that I bought it.
Reviewed by John:
2004 Cummins 5.9 300000+ miles still has cross hatch in the cylinders
Reviewed by Ricky:
Awesome oil I run 10/30 in my 6.0 powerstroke so smooth and great
Reviewed by Jarrod:
I use this oil in my 2006 Duramax with 180,000 and my 2006 Mercruiser. Oil works great.
Reviewed by Terrance:
I've used this product in my '98 Dodge 3500 Diesel 4x4 for 18 years. It has worked excellent for me the whole time. I've tried other products before I tried Amsoil and they failed excessive heat and caused my truck to clatter. Amsoil works flawlessly for extended drain interval and for storage. I plan to continue Amsoil products in the near and distant future exclusively.
Reviewed by Andy:
This oil is amazing i change it every 20 miles i also picked up 3.5 mpg after 1st oil change 10 years ago love it and recommend to every gm diesel owner out there
Reviewed by Sammy:
Been using AMSOIL for over 20 years. Great products!
Reviewed by Mike:
I use it in my Chevy gas trucks one has over 307000 miles on it never been into it 5.3L LS
Reviewed by Ken:
Great oil, I have been running this in my 2500 4x4 dodge diesel for 10 plus years. 302,000 miles on it. Also use it in my Kubota Tractor, run it for 15,000 miles per oil change, change oil filter at 7500. I have sent the oil to lab several times, after 15,000 miles running time, oil always comes back good, never breaks down, good product,
Reviewed by Herbert:
I have gotten great results with the oil. Have gone 40,000 miles on my oil changes. And I am taking baby steps towards 100,000 miles and beyond.
Reviewed by Rob:
Freat
Reviewed by Richard:
I use in my 2001 F350 powerstroke on pull 35 ft 5th wheel.
Reviewed by Vipra:
15w40 AME & a 15micron Donaldson P551018 for my annual oil/filter changes.
From Southern summers to Northern winters, UOA shows that this combo can't be beaten for my over fueled, compounded decathlete 12v Cummins.
Don't ever stop making this outstanding CI4+ oil.
Reviewed by Usgr:
Been using since 2003 in Duramax. Handles all climates.
Reviewed by Easy:
Switched to amsoil in my 2006 f250 powerstroke. My truck now starts much better, and runs quieter and smoother!
Reviewed by JC:
I use this oil in my JD 4720, I am very happy with it, it serves my purpose for what I use it for.
Reviewed by Raney1999:
Only oil I've ever used in my 6.7 Cummins for last 100k aside a rotella hear and there. Also use the amsoil oil filter. Works well together !
Reviewed by Danny.W:
I've run Amsoil in my 05 Cummins 5.9 for around 200k. And I've used all the different diesel oils Amsoil has to offer from highest of performance to the eco price. But In my leaky 300k plus and climbing work diesel. the marine oil always comes out with just about as much as I put in 10k ago. And the others I would sometimes be up to 3Qt short when drained. Like it's gets so thin that it finds completely new ways to seep out !! But that why I like to order the heavier oil. Lastly my whole truck runs on Amsoil rears,difs,transfer and engine, and I strongly believe that Amsoil is the soul reason why my Cummins runs as good as it does at 310k miles!! Thanks
for the spectrum or synthetic lubes to chose
from!! Two thumbs high from this guy!!
Reviewed by Gary:
It does not break down like other oils, doesn't get up, or foam up. Longer time between changes.
Reviewed by Ddenham:
Great product, been using this product for years.
Reviewed by Cope:
Amsoil heavy duty 15w-40 marine diesel oil has proven to me that it will protect my Cummins engines. I have older high mileage Dodge trucks that get driven on the highway, gravel roads in -15F cold and 100F heat and the lab results from my oil samples have continually came back great. At a minimum I put double the factory recommended mileage on this oil before changing, depending on driving conditions.
Reviewed by ROLAND:
Reduced engine noise (duramax)
Reviewed by Cummins lover:
I've been using Amsoil diesel and marine for many years I drive 200 miles a day in my Cummins in and out of petroleum refineries 6 to 7 days a week and I work my truck hard! Amsoil has never let me down! This is a great product
Reviewed by Jeff:
I have been using Amsoil in my 2003 Chevy Duramax for its entire life with great results.
Reviewed by Tim:
Been using in my 02 duramax since I bought it in 06 oil stays very clean never black like many diesels
Reviewed by Charles:
This 15w-40 Marine oil is all I use in
both my 2001 300hp Mercruiser boat engines since 2011. Why you might ask? 1) Only oil that has shown to lubricate the turbo blades on my son's boat diesel super-charger.
2) When son's oil hose ruptured at full engine speed, repair mechanic stated that engine only survived due to the oil's lubrication properties.
Reviewed by Kerry:
We have been using this product in our 2004.5 Dodge diesel since 2010. The truck had 110K miles on it when we switched over and added the micro-filtration unit. We now have some 329K miles with about 120K miles of that amount while hauling commercial freight. Now back to my daily driver and still using this oil.
Reviewed by Chum:
Product is great. 8-10,000 miles between oil changes. Price is right. You might as well go with the best.
Reviewed by Matt:
It helps my 7.3 powerstroke start better since the injectors are oil fired it will start when 0 degrees without being plugged in
Reviewed by Flyoften:
Oil is like a lot of things where the positive traits are hard to quantify. You just have to know it's good and working. I run it in a Ford 6.0 so it has to be good.
Reviewed by LEXUSMAN:
I'VE BEEN USING AMSOIL SINCE 2004 AND I JUST LOVE THESE PRODUCTS. IN MY OPINION AMSOIL IS THE BEST OIL OUT THERE NOTHING COMES EVEN CLOSE. I HAVE A 2002 TOYOTA SIENNA WITH 570.000 MILES YES YOU SAW IT RIGHT 570K MILES AND THAT THING JUST KEEPS ON GOING AND GOING, IT JUST DOESN'T WANT TO QUIT. STILL ORIGINAL ENGINE AND TRANSMISSION. PEOPLE TOLD ME TO GET RID OF IT BUT I TELL THEM IT'S NOT THE TIME YET IT STILL RUNS LIKE A CHAMP AND EVERYTHING IS
WORKING ON IT. I USE AMSOIL PRODUCTS ON MY OTHER CARS AS WELL AND A FEW OF MY FRIENDS GOT HOOKED ONCE THEY TRY IT AND THEY NEVER WENT BACK TO THE OIL THEY USED TO USE. THANK YOU AMSOIL FOR YOUR GREAT PRODUCT, KEEP UP THIS AWESOME WORK AND I WISH THAT AMSOIL TO BE AROUND FOR THE NEXT 100 YEARS.
BEST WISHES AND GOD BLESS AMSOIL!!!! ISTVAN.
Reviewed by Donkey Boy:
All we use in all our truck&tractor,
Reviewed by Me:
I have been using this oil sense I bought my 07 Dodge Ram diesel new 12 years ago. I go 15k between oil changes. I'm glad I started using this Oil and the by-pass system when I did. I have 250k on my truck now and plan to go another 250k. Amsoil has been great every time I place an order as well.
Reviewed by Crowley:
Have been using heavy duty diesel marine synthetic motor oil in my duramax work truck for last 70,000 miles. Seems to have superior protection and less breakdown under heavy loads and extreme conditions.
Reviewed
by Marv:
Motor oil
Reviewed by Bullwinkle 119:
This vehicle I drove everyday for work. Change the amsoil 15-40 marine/ diesel every 7,000 to 9,000 miles. Chose the 15-40 because of the drastic temp changes in Texas. The transmission gave up motor still strong didn't want to put any money in it sold it to a friend. Amsoil is an amazing product. Well worth the money.
Reviewed by M Grieshop:
I run this oil all winter long,every winter
Reviewed by Bigguns:
I use this oil in my 7.3 liter van for the fact that it does great in the cold weather that I get into. I travel a lot in the northern states and it always turn over.
Reviewed by
Steve:
After taking professional training for oil analysis it occured to me this was a suitable option. I have a diesel truck that gets infrequent use and having a 14 tbn gives me comfort in fighting acidity while in storage.
Reviewed by ShovelJockey:
I've got a strong running 7.3 with 292,000+ on the clock. Have been using another oil with excellent UOA reports and getting close to 10k on oil changes. Decided a while back it was time to see what this Marine Amsoil was all about. Immediately noticed my injectors were much, much quieter. Will be sending a sample in for testing in about 2000 miles and see how things compare.
Reviewed by Roy:
I use this in my turbocharged Subaru during the cold months. It has loads of zinc and phosphorus so it protects the turbo, and its high viscosity index provides great cold start protection as well as high temperature protection in the turbo bearings. My motor and turbo have over 80,000 miles on them and are still running like new.
Reviewed by Reree:
Does what it says it does, went from running my oil from 5,000 miles to 20,000 miles. Saves money and time , engine temp runs cooler when under a heavy tow going up a grade, oil doesn't smell burnt when doing a change easier start up in cold whether with not having the truck plugged in. Extremely satisfied with this product!
Reviewed by Eric:
I change oil every 15k and I think is still good. 350 ml Bluetec
Reviewed by Marmon:
Has improved the performance , better fuel economy ,easier starting saves money from not having to change oil.I also use cetane boost and injector cleaner
Reviewed by speedy:
I feel that it is a superior product.
Reviewed by Jack:
I run an Amsoil bypass filter system and I am religious about changing filters and doing oil analysis. My old "rig" has always started well in winter and I only have to add oil when I change my filters.
I have only changed my oil 4 times in the 17 years I've owned her. I would recommend all Amsoil products I have used.
Thanks to you all
from me and my truck for helping us keep on keeping on.
Reviewed by Ted:
Works good when dealing with interior
Alaska weather of - 40 degrees.
Reviewed by Randy:
I use amsoil in everything I own! Works great in my 06 duramax,01 powerstroke and Canam defender side by side. Peace of mind for sure!!
Reviewed by Mark:
I use this oil for my 1999 Ford F250 7.3 liter diesel. This oil has very good longevity. For a diesel I change this oil about every 10,000 miles. It cuts down on oil change intervals. I am sure it could go much longer.
Reviewed by Mr. Fix it:
I have been using this oil in my Sequoia, Continental, and motorhome for 15 years. Tell me what other oil lasts 25 k in a gas engine?
Reviewed by Derek:
I cannot say enough about this oil. My truck starts easier, runs better, and probably gets better fuel economy. I "push" Amsoil on all my friends because I believe in it so much.
Reviewed by Spotted puppy:
Amsoil is the only oil, grease and lubes that have been used in our 2001 F-250. It now has 210,000 miles with no use of any oil. This is our second diesel truck that we have use only amsoil. The other truck had 300,000 when we sold it. It did not use any oil either.
Reviewed by Master Craft:
I use this oil in my Master Craft boats and it keeps them working perfectly year after year after year.
Reviewed by Machineman:
Have used this oil for years, would not use anything else in my diesel truck
Reviewed by Daniel:
I've used AMSOIL products for years. I have an 2004 F350, 6.0 liter and this is the only oil I run. Amsoil keeps the engine clean and long lasting. Also use AMSOIL in my 2007 Expedition. Both vehicles have close to 200,000 or more than. Still running strong.
Reviewed by Chris:
Run these fluids in all vehicles
Reviewed by Barry:
My diesel will use nothing else!
Reviewed by Tw:
Daily driver ,200000+ miles runs like new
Reviewed by Whododgeit:
It great oil and keep engine running life
Reviewed by ron:
1995.dodge.2500.12.valve.5/9.cummings.diesel.only.500.miles.since.change.have.notice.better.fuel.efficiency
Reviewed by Buck:
Works perfectly
Reviewed by L. Williams:
Greetings,
I have a 2001 Hummer H1 and I recently 'rescued' a 1995 Hummer H1. Now, both of these vehicles are
getting closer to the Classic status. I am bringing the 1995 back to life. I have changed the diff oil, hub oil, engine oil, trans oil, and coolant with Amsoil. The 1995 is running strong now.
I take the vehicles out in the wilderness. I see no reason to risk my family getting stranded by using a cheap/sub-standard product.
Adventure on!
Reviewed by LBZ Duramax:
I've been using Amsoil 15W-40 Heavy-duty Diesel and marine oil in my 2006 Silverado 2500HD for 10 years now. Oil and filter change intervals average around 12,000 to 18,000 miles.
The truck now has over 355,000 miles on it and it still runs great! I never have to add any oil between oil changes either. If you are on the fence about using this oil in your vehicle, I say, go for it! You won't regret it!
Amsoil is top of the line!
Reviewed by Jason:
I have an 06 Dodge with the Cummins. These 'older' diesels required a CI4+ oil. There is much debate in the oil world about the qualities of the newer oils vs the older ones - specifically that the old CI4+ oils had more detergents in them, which the older engines liked better. Even though the newer oils are backwards compatible, they apparently do not have the same detergents in them. This has been the only CI4+ rated oil I can still find. Its the only oil I use in the Cummins.
Reviewed by Mr Diesel:
Used this oil for 27 years and never had a oil leak or any engine failure. Put 300,000 miles on Dodge TURBO Cummins, check but never had to adjust valves. Only oil I will use.
Reviewed by Eric:
Been using this on 7.3 heui truck oil shearing monsters. I'm at 9k and been pushed to 15k for next oil analysis definitely a efficient product and same $$$$ on oil changes..
Reviewed by chin00kie:
I maintain seven vehicles so changing oil could be a full time job. I use Amsoil because it is the best oil made and the best filter in the industry. My twin sons just became 16. For their birthday I had them learn how to change the oil in their trucks by converting them to Amsoil . This oil seems to be better suited to my older VW Jetta than the other Diesel oils. I use less of this oil. My car has nearly 300,000 miles and has always used about 4 oz of oil every 500 miles. With this oil that amount is cut in half.
Reviewed by Mark:
I also use the motorcycle kit for oil and filter changes in my Harley Davidson
Reviewed by Dan:
When I first heard about Amsoil I was really surprised by the quality of ALL of Amsoil's products. Amsoil strives to produce the best product for the most efficiency, longevity, and power from any engine. My first oil change using Amsoil after I started up my truck and got all the new oil moving around I noticed my 260,000 mile 6.0 Powerstroke ran smoother and I can rely on Amsoil to keep my old ford running like new for years to come. All I use is Amsoil in all of my vehicles.
Reviewed by
Odie:
I have 234000 miles using this oil,and My engine performs as good today as it did when new.
Reviewed by Brian:
I started using this oil after the break in period and have used it with an Amsoil #099 Filter changing both each year and it seems to do very well. The truck neither leaks or burns any oil since I purchased it in January 2000.
Reviewed by Kmetz:
Best product I've ever used and will Co to use to use for the life of this diesel as well as my follow ons.
Reviewed by Joe:
I rely on information that I get from Amsoil and write ups on engine oil that I find in magazines and on the internet as well as word of mouth. I've been very satisfied with the oil.
Reviewed by Danny:
I use this product in my '79 Mercedes diesel. In cold starts it can not be beat. It holds up well for extended drain intervals and keeps old diesel running smooth and clean. For an old diesel(pre 2007) there is nothing that matches it.
Reviewed by Bird:
I run this oil in my 2001 F350!
Reviewed by Bird:
I run this oil in my 2001 F350!
Reviewed by 904Bronco:
I am almost at 200K on my Ford 2002 Super Duty Truck and hope to go to 300K + miles. Very happy with Amsoil quality and prompt service/shipping. I have ventured out and used other related diesel products in my truck with great success as well. Thx for providing a great product.
Reviewed by Kevin:
I have been using this oil seance 2005. I got a 2004 F-250 with 170,000 miles. I wouldn't use any other oil
Reviewed by Kevin:
I have been using this oil seance 2005. I got a 2004 F-250 with 170,000 miles. I wouldn't use any other oil
Reviewed by Wayne:
I have been using Amsoil heavy duty diesel and marine oil for the past 12 years in my 2004 GMC Duramax 2500HD truck. I have pulled a trailer all over this county and the engine has 360,000 and running strong.
For what you pay for a truck, it's worth using the best lubricates out there to get the most mileage.
Reviewed by ddub:
My 2001 F-350 has been running with Amsoil the whole way. A mechanic told me to do it. Check back with me in another 16 years. (-;
Reviewed by Matt S:
I've run Amsoil products for a combined 750,000 miles between my vehicles. Never had a breakdown from a related issue. Nothing but the best
Reviewed by Old Beater:
Excellent oil, no issues with winter starts in Canada, outstanding service from Anne & Alex as usual.
Reviewed by PJ:
I have been an Amsoil customer for almost twenty years. I use Amsoils in all my vehicles and am totallt satisfied with the performance.
Reviewed by Spray of gravel:
I have used only Amsoil 15-40 Heavy Duty Motor Oil in my service pickup since it was new. It has over 509,000 miles with out any motor repair and I lost all my oil twice when some external oil lines broke but Amsoil saved my engine.
Reviewed by Campspringsjohn:
I've been running the 15w-40 Heavy Duty Diesel and Marine Oil for years in all my work trucks. I've owned 3 7.3 psd Fords, and a 2008 with the 6.4. Though this oil is not recommended for the 08, it has been deleted and does just fine in it. (if your truck is not deleted, use the recommended oil) I use Amsoil oil filters and do extended oil changes. 15,000 miles on all the trucks. Though I don't do oil samples on every oil change, whenever I have, they always come back good. In fact, I could probably go to 20,000 miles if I want to.
Reviewed by Gazza:
Love all amsoil product from racing jet skis to now running it in my 41 foot boat.
Canada
United States
Reviewed by Peter Jaeger:
15/40 HD Marine
Awesome oil for my 2010 F350 6.4. Deleted in 2011 when I started using the Amsoil and now have 243,000 Km on Sept 2020 with no issues. Runs great. Change oil once per year but change oil filter every 6-7 thousand Km. Just got oil analized and all is great,,, don't need to change oil yet but I will soon for piece of mind and yes it will be Amsoil again.