Tuned Yota · Independent Authorized AMSOIL Dealer · Lakeville, Minnesota, USA · This website is owned and operated by an independent AMSOIL Dealer and is not AMSOIL INC.
Heavy-Duty 5W-40 100% Synthetic Diesel Oil
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Heavy-Duty 5W-40 100% Synthetic Diesel Oil is a 100% synthetic formula developed for hard-working turbodiesel pickups and equipment — 4X better wear protection than required by the Detroit Diesel DD13 scuffing test, with low volatility that minimizes oil consumption.1
Why this product
- 4X better engine wear protection than required by the Detroit Diesel DD13 scuffing test.1
- Minimizes oil consumption — low volatility (burn-off) with excellent film strength at high operating temperatures.
- 5W-40 is specifically designed for the demands serious turbo-truck enthusiasts put their diesel pickups through.
- Exceeds the latest API CK-4 specification.
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Become a Preferred Customer under Tuned Yota — up to 25% off retail, points, exclusive promotions and free gear. The membership pays for itself in about two oil changes.
Become a Preferred Customer →Heavy-Duty 5W-40 100% Synthetic Diesel Oil — FAQ
No — synthetic oils do not cause engines to leak. AMSOIL diesel oils are fully compatible with modern seal materials and are formulated to condition seals, keeping them pliable. They're safe in both new and high-mileage engines.
Both exceed the API CK-4 specification. Heavy-Duty delivers 4X better wear protection than required by the Detroit Diesel DD13 scuffing test; Signature Series Max-Duty delivers 6X, with reserve protection that allows extended drain intervals — it's the pick for hardcore enthusiasts and owners who want the best.
Signature Series Max-Duty is suitable for applications specifying API SN+ and earlier, making it ideal for mixed fleets. Check your owner's manual for the specified viscosity and rating.
Keep reading
1 Wear-protection comparisons are based on the requirements of the Detroit Diesel DD13 scuffing test. Price shown is AMSOIL's current online retail price, synced weekly. Checkout completes on amsoil.com; orders are sold, shipped and fulfilled by AMSOIL Inc. Tuned Yota is an Authorized AMSOIL Dealer.