How Are Octane and Cetane Actually Used to Measure?

Fuel ratings can be confusing. You’ve probably heard of Octane when filling up at a gas station, and maybe Cetane when talking about diesel. But what do they actually mean and how do they impact your vehicles?

Octane is a measurement for gasoline fuels. It indicates a fuel’s resistance to knocking or premature ignition under pressure. High-performance gasoline engines, especially those with turbochargers or high compression ratios, need high-octane fuels (91-94) to prevent knocking, which can damage engine components over time. Regular gasoline has an octane rating of 87, which is sufficient for most standard gasoline engines.

On the other hand, Cetane is used for diesel fuels. It measures how easily the fuel ignites under compression in a diesel engine. A higher cetane number means the fuel ignites faster and burns more completely, resulting in smoother engine operation, quieter performance, and reduced emissions. Traditional petroleum diesel has a cetane number of 40-55, while renewable diesel boasts much higher cetane numbers (70-90), giving fleets significant performance and maintenance advantages.

Here’s the key difference:

• Gasoline engines want high octane to prevent early ignition.
• Diesel engines want high cetane to ensure quick ignition.

They’re opposite in what they measure but both are essential to engine performance.

At Energie Fuel, we’re helping businesses make fueling smarter by providing access to the needed octane of gasoline and high-cetane renewable diesel that keeps your fleet running cleaner and more efficiently at the wholesale prices you deserve to pay.