Get the Best Synthetic Engine Oil and Transmission Fluid for your Semi-Truck!
Amsoil is the best made in USA synthetic on the market! Lab tested for performance!
4X to 6X More Wear Protection
Maximize Engine Life
Less Downtime and Maintenance
High Quality Raw Materials
Products Tested for Performance
Reduced Oil Consumption
Viscosities available are 5W-30, 5W-40, 0W-20, 10W-30, 15W-40, 0W-40, 10W-40, 5W-20, 15W-50 (Click below for complete list)
Heavy-Duty Engine Protection
Your semi deserves the best protection to prevent deterioration on rings and/or cylinder liners which will increase oil consumption, less compression, horsepower and fuel economy. Independent testing has demonstrated 4 times more protection which means less downtime and costly repairs.
Extreme Temperature Protection
Superior heat resistance compared to regular diesel oil. Also flows better in cold temperatures for easier startup while giving you maximum engine protection.
Minimize Oil Consumption
Our Max-Duty oil has less burn off which means less consumption while preventing vapors into the combustion chamber. Our oil is tough as nails!
Made in U.S.A.
We are proud of our synthetic oils which offer superior protection to vehicles, trucks, motorcycles, and boats. All Amsoil products are backed by a limited liability warranty. We are the first in synthetics, since 1972!
Browse our line of synthetic diesel engine oils by weight. Our oils come in a 1 quart bottle, or for better discounts a 1 gallon jug, 2.5, 30, or 55 gallon drum, or a 275 gallon tote! We also have Donaldson P-Series Lube Filters. Search your truck to see all available filters.
High Quality Raw Materials
Amsoil Backs Up Every Claim with Product Testing
Reduced Oil Consumption
Real Testimonials
"Awesome diesel oil for my truck, always order, great cold starts just last time didn't get any cool stickers that I like so much, please send the stickers! :)"
Harry
"been using Amsoil diesel for 120 thousand miles already, even did an oil sample test and the results come back great, feel better using this synthetic for my Cummins 6.7L"
Dennis
"engine sounds better when I use this, my Chevy truck must love it, will not be going back to the other brand I use to use, solid product with solid testing"
Timothy
Why is Amsoil Better for Your Semi?
It is Formulated for Superior Diesel Engine Protection. AMSOIL Heavy-Duty Synthetic Diesel Oil is formulated for tough equipment. It is engineered to provide 4X more wear protection, giving you the edge to keep trucks and equipment running at peak performance. AMSOIL Heavy-Duty Synthetic Diesel Oil offers outstanding value and provides excellent protection for customers looking for an upgrade over conventional, synthetic-blend or competing synthetic diesel oils.
Heavy-Duty Engine Protection
Wear on rings and cylinder liners leads to increased oil consumption and loss of compression, resulting in reduced horsepower and fuel economy. Third-party testing shows AMSOIL Heavy-Duty Synthetic Diesel Oil delivers 4X more wear protection to help maximize equipment life and reduce maintenance costs and downtime.
Viscosity Control
Formulated with advanced synthetic base oils and detergent/dispersant additives, AMSOIL Heavy-Duty Synthetic Diesel Oil minimizes viscosity change while keeping soot particles suspended independently, helping prevent the formation of larger, wear-causing particles. Lower volatility also helps AMSOIL Heavy-Duty Synthetic Diesel Oil retain its viscosity after high-temperature service for added engine protection and increased fuel economy.
Stands Up to Harsh Temperatures
AMSOIL Heavy-Duty Synthetic Diesel Oil is formulated to deliver improved heat and oxidation resistance compared to conventional diesel oils. It provides clean engine operation and helps maintain power and fuel efficiency for superior engine performance. AMSOIL Heavy-Duty Synthetic Diesel Oil also flows dependably in cold temperatures for easier startup and improved engine protection.
Reduces Oil Consumption
AMSOIL Heavy-Duty Synthetic Diesel Oil has a low rate of volatility (burn-off), reducing oil consumption during operation and passing less oil vapor into the combustion chamber. It provides up to 66 percent less oil consumption than required by the API CK-4 standard in the Caterpillar-1N oil consumption test.