Whatever the weather. Whatever your fleet. Duron Synthetic 5W-40 is the one soot-fighting heavy duty engine oil that can handle it all. In fact, when tested against non-synthetic 15W-40, Duron  Synthetic pushed extended drains up to four times longer. With extended drains comes lower oil consumption, less maintenance and smoother running engines. All of which saves you money.

But it doesn’t stop there. Duron Synthetic 5W-40 equaled or outperformed a leading competitor’s more expensive full synthetic heavy duty oil in critical wear and tear tests.