I use this oil in my truck and there is a noticeable difference in hot oil pressure. With other oils the hot oil pressure is about 38 PSI and with AMSOIL 15W-40 the hot oil pressure is about 42 PSI. The cold start valve noise is noticeable quieter with the AMSOIL than with other oils.
Been using these products for over 20 years highly recommend best in the business AMSOIL. We got out of a 89 Ford straight, six 450,000 miles.
it actually still started, but motor had no more power
I absolutely love the protection and performance from amsoil. My truck runs so much better and actually see a slight increase in mpg since switching to amsoil.
My 97 power stroke always made a lot of deisol rattling noises, especially when cold..Amsoil made it quiet and ran much better...I pulled a heavy 8 k camper, 2 k miles and I am sure fuel milage was better.. definitely have mo power...in the big picture it's cheaper to use Amsoil.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
5w-40
By 
CHRISTOPHER, 
a 
Verified Buyer 
on 
October 30, 2024
I highly recommend this oil for any diesel platform! My 2014 6.7 Cummins loves this oil!
This is the 3rd diesel truck I have owned over the past 20 years. I started using this oil after being re-introduced to the newer and better way to access getting Amsoil products. I have been a long time fan of Amsoil, as I was in the racing community in the 60's -2000's running USAC several divisions and the NASCAR Modified and Super Modified divisions. I had Amsoil as a sponsor for many years of that time period. I stopped using Amsoil after racing due that it was so difficult in finding someone who sold it and would not want to sell you large quantities, if you wanted to buy if for a normal consumer need.
Once I found that I a general consumer was able to purchase it from your website and become a discount customer I was all in. I did this in 2015 and have converted all my vehicles to amsoil products. This Diesel oil is great as it has reduced running temp of my motor and turbo, the coolant has increased the cooling quality and has the additive that i no longer have to buy what Ford wants to regen the coolant due to a mental degrading in the engine and cooling system. I also use the Amsoil micro oil filter for each oil change. The truck has just turned over 170K and is still running great. I change the oil every 20K with filter. The truck is a 2012 Ford F350 Super Duty 6.4 Powerstroke Diesel.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
F350 Super Duty
By 
ROBERT, 
a 
Verified Buyer 
from 
St. Augustine, FL. 
on 
October 24, 2024
I have been using this in my truck since 2018. I like the quality of this over the Motorcraft. And it is actually less than a dollar more per quart the the Motorcraft full Synthetic.
My current truck (2006 lbz duramax) has had Amsoil since its first oil change. Oil has been changed every 25k miles and filter every 10k. At 247,000 miles truck is running strong with zero blow by and burns no oil between changes. My opinion Amsoil makes a great product!
I have been using Amsoil 15-40 diesel oil in my 2007 Chevy Duramax since I purchased new in 2007. Never any issues, no oil consumption and easy cold weather start-up.
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