What Is Cetane and Why Does It Matter?

Cetane relates to how readily diesel fuel ignites during combustion. In simple terms, a higher cetane number usually means the fuel ignites more easily and with less delay after injection.

Why Cetane Matters

A higher cetane number can help improve cold starts, reduce ignition delay, smooth engine operation, reduce diesel knock, and support more efficient combustion. The benefit you notice depends on the fuel, engine, temperature, and operating conditions.

Does Higher Cetane Improve MPG?

Some customers report improved fuel economy when cetane is improved, but results vary. Fuel quality, vehicle condition, load, driving habits, idle time, weather, and route can all affect mileage.

Which Opti-Lube Product Is Best for Cetane?

Boost! is the best choice when maximum cetane improvement is the main goal. Summer+ and XPD All-Season also provide cetane benefits as part of a broader additive package.

Need help choosing? Start with Opti-Lube diesel fuel additives or review our FAQ for dosing, storage, and compatibility questions.