Get the Best Heavy Duty Synthetic Diesel Oil for your Semi-Tractor Trailer, Big Rig, 16 or 18-wheeler Truck

AMSOIL synthetic technology delivers heavy-duty protection!

4X to 6X More Wear Protection

Maximize Engine Life

Less Downtime and Maintenance

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!

Search your truck's oil by clicking below

Browse our line of diesel 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 250 gallon tote!

Other viscosities available such as 5W-30, 5W-40, 0W-20, 10W-30, 15W-40, 0W-40, 10W-40, 15W-50, 20W-50, 5W-20 (Click below)

High Quality Raw Materials

Reduced Oil Consumption

Amsoil Backs Up Every Claim with Product Testing



"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! :)"
synthetic diesel for my truck
"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"
synthetic diesel for my truck
"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"
synthetic diesel for my truck

We also have made in USA synthetic oil for your car, boat, motorcycle, truck, semi tractor, snowmobile, atv, jet-ski or utv. Click on button below to explore the best oil to reduce downtime and repairs.