Your diesel engine isn’t just a means of transportation—it’s a high-stress power plant that handles heavy loads, intense heat, and grueling conditions. Give it the ultimate defense with Amsoil Signature Series Diesel Synthetics. Engineered with top-tier synthetic base oils and advanced detergent additives, this premium formula delivers up to 6X more wear protection than required by leading industry standards.
Whether you’re towing heavy payloads, running a commercial fleet, or driving a daily-duty turbo diesel, Amsoil Signature Series resists thermal breakdown, controls soot buildup, and extends engine life.
Upgrade to maximum uptime, better fuel economy, and unmatched cold-weather startup protection. Because your diesel deserves the best.
Discover the reasons why people loves us and become your go-to partner.
I noticed on the Amsoil website when you add your make and model truck and your address it will automatically put the exact product for your vehicle in front of you. I have a 2021 Ram with the 6.7 Cummins that has the hydraulic lifters that are oil specific and I live in Oregon with more temperatures and the website put the 10W-30 that is the preferred oil grade by Cummins for the 6.7 with hydraulic lifters in my climate and how many parts counters are going to do that or let you walk out with 15-40. I have zero problem paying more for better oil in a vehicle that I you invest 80 to a 100K into.
Bottom Line
Yes, I would recommend this to a friend.
By Chip, a Verified Buyer from Oregon on July 05, 2026
Love the AMS oil difference! My oil temps run a few degrees cooler when towing in this hot summer sun! Thanks AMS
Bottom Line
Yes, I would recommend this to a friend.
By BRENT, a Verified Buyer from New Mexico on July 06, 2026
Very fast service and great product
Bottom Line
Yes, I would recommend this to a friend.
By MARK, a Verified Buyer from Utah on July 03, 2026
