AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
DMEQT (DMEQT-CA)
Quart Bottle
Case of 12
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
DME1G (DME1G-EA)
Gallon Jug
Each
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
DME1G (DME1G-CA)
Gallon Jug
Case of 4
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
DMETP (DMETP-EA)
2.5 Gallon Jug
Each
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
DMETP (DMETP-CA)
2.5 Gallon Jug
Case of 2
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
DME55 (DME55-EA)
55 Gallon Drum
Each
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
DME27 (DME27-EA)
275 Gallon Tote
Each
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil
4.9 star rating
Based on 1,284 reviews
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.
Was this review helpful?
5 star rating
Fast shipping, and great a product
By 
ANDREW, 
a 
Verified Buyer 
on 
February 01, 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.
Was this review helpful?
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.
I have used the heavy duty oil from amsoil, which is great protection. Motor was still little noisy, and switched oil to this signature series and made the motor quiet down alot and run smooth. It's a good one to run.
I use to use Rotella T5 10W30 and was getting decent mileage and protection. When Shell couldn't get the additives to make the T5 oil I changed to Amsoil 10W30. Best decision I could have made! The oil gets me about .5 to 1 mpg increase. I love this oil! I'm glad I switched and don't plan on ever going back!
Bottom Line
Yes, I would recommend this to a friend.
Was this review helpful?
5 star rating
Great stuff!
By 
CHARLIE, 
a 
Verified Buyer 
on 
January 14, 2025
Love this oil.
Bottom Line
Yes, I would recommend this to a friend.
Was this review helpful?
5 star rating
Newer Diesels
By 
CURTIS, 
a 
Verified Buyer 
on 
January 09, 2025
I just bought a newer diesel 5th wheel hauler to replace our aged 2002 Duramax. The old truck only used Amsoil 15w-40 Marine Diesel Oil. The new truck takes 5w-40 full synthetic or 10w-30. Since the marine grade doesn’t come in 5w-40, I used the signature series. Looking forward to many years with this new truck using Amsoil.
I began using the Signature 5W-40 Synthetic Max-Duty Diesel Oil in my 2024 New Ford F-350 with the new HO Diesel engine this past fall. I manage a large farm in Central KS and work in very extreme conditions. I’ve been more than happy with it’s performance and trust AMSOIL superior products will protect my engine for a long, long time.
I've been using AMSOIL 5W40 Diesel Oil in my John Deere 1025r for more than 10 years. I store the tractor outside under cover without benefit of a block heater. Even on the coldest, below zero mornings, the tractor starts right up with just one cycle of the glow plugs. Year round protection in all temperature extremes is why I've been an AMSOIL fan for more than 25 years.
All Amsoil products are great but especially the quality of their signature line. I own a Ram 3500 (non dually) with the Cummins 6.7L and my engine runs whisper quiet with it. I can always tell quality oil with how long the engine takes to warm up. Not only that but the viscosity lasts longer than other oils. I'm something of a nerd to checking how thin the oil is when it drains and I always feel like I've changed my oil too soon. A great product hands down.
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