10/03/2026
Maximize Your MPGs. Protect Your Power.
For the diesel owner who demands both unrelenting strength and maximum fuel efficiency, there is AMSOIL Signature Series Max-Duty 5W-30 Synthetic Diesel Oil.
Modern diesel engines and mixed fleets shouldn't have to choose between heavy-duty protection and economy. Our 5W-30 Max-Duty formula is specifically engineered to provide the fuel-saving benefits of a lower viscosity oil without compromising the legendary wear protection AMSOIL is known for.
Fuel Efficiency without Compromise:
* Maximize Every Gallon: Formulated to reduce internal friction, this oil helps your engine turn fuel into power more efficiently, keeping more money in your pocket at the pump.
* Superior Viscosity Control: Even under extreme heat and heavy loads, Signature Series resists the thickening effects of soot and oxidation. This ensures your oil maintains its ideal flow, reducing drag and optimizing efficiency throughout the entire drain interval.
* Cleaner Turbos, Better Performance: Delivers up to 60% better turbo cleanliness, ensuring your turbocharger operates at peak efficiency for better air-to-fuel ratios and improved combustion.
Maximum Duty Protection:
* 6X More Wear Protection: Outperforms the Detroit Diesel DD13 Scuffing Test by 600%, proving that a fuel-efficient 5W-30 can protect just as well as—if not better than—a traditional 15W-40.
* 76% Less Oil Consumption: Low volatility (burn-off) keeps the oil in the engine and out of the combustion chamber, maintaining peak efficiency and power.
* Sub-Zero Cold Starts: Flows effortlessly down to -45°F, reducing startup drag and wear while getting you on the road faster.
One Oil for Your Entire Fleet. Signature Series Max-Duty is also compatible with gasoline engines, making it the perfect choice to simplify maintenance and maximize efficiency across your whole operation.