The Importance of Cetane in Diesel Fuel

Cetane Importance
August 28, 2020

There is obviously a big difference between gasoline and diesel fuel. From the combustion process and power outputs to the differences in efficiencies, the composition of each fuel type is a true science. Regular unleaded gasoline is considered a flammable liquid, which means it only requires a spark to ignite and power an engine. Diesel fuel on the other hand is classified as combustible, which means it requires a compression and heat source to generate energy. The energy generated by diesel fuel and this combustion process is far greater than the energy produced by gasoline. A key component within diesel fuel and it’s combustion process is the cetane level.

Cetane is a hydrocarbon within the fuel that ignites under high pressure. Every diesel fuel has a cetane rating that represents the quality and performance of that particular fuel. The higher the number, the more efficiently the fuel burns. For example, a fuel with a cetane rating of 50 is going to be far more efficient than a fuel with a cetane rating of 40. Most diesel engines operate best with a cetane level of around 48 or 50. When the cetane number is lower than this, the fuel will have a longer ignition delay, which requires more time for the fuel to fully burn and provide power to the engine. An efficient fuel is a fuel that ignites quickly and completely, leaving as little unburned fuel behind in the combustion chamber as possible. It also provides easier starts with less emissions.

The problem with diesel fuel is that you really never know what you are getting when it comes to fuel quality. With today’s Ultra Low Sulfur Fuel (ULSF), there is inconsistency from fuel station to fuel station. ULSF is extremely dry, lacks proper lubricants, and has variable cetane levels making it difficult to understand if your engine is getting what it needs to perform as you expect it to. An easy solution to combating the variable quality of fuel, is to add a multi-purpose additive like Hot Shot’s Secret Diesel Extreme or Everyday Diesel Treatment (EDT). Not only does Diesel Extreme or EDT add benefits like lubricating properties and rust inhibitors, but it also increases the cetane level by up to seven points, resulting in better fuel economy, added horsepower and just an overall better burn of fuel. The cetane improver in both formulas consists of special nitrates that work to speed up the oxidative process of fuel during combustion resulting in more power, improved mileage and less soot. If you want to be sure every tank of fuel you run through your truck is quality fuel, it is essential to add a treatment of Hot Shot’s Secret Everyday Diesel Treatment each time you fuel up.

With an increased cetane number, cold starting is improved, and less black smoke is seen as a result of the improved combustion efficiency. Less hydrocarbons and particulate matter in your exhaust reduce the blocking of your Diesel Particulate Filter and using Diesel Extreme in your fuel has been shown to have 83% less DPF regenerations, saving you time and money. Increased cetane levels have also shown to improve fuel mileage and power. Fleet tests with Diesel Extreme have shown an improvement in fuel mileage up to 7.3% due to the combination of our injector cleaner and cetane improver. This combination is also responsible for restored throttle response.

The science of diesel fuel goes far beyond a simple cetane rating. However, by understanding the cetane level of your fuel and how it impacts the performance of your engine, you are dramatically increasing the fuel’s ability to burn. Think about it over the lifetime of a vehicle. If you were to run diesel fuel with an average cetane rating of 40 for as long as you own the
vehicle, you would have wasted far more fuel and much more money than if you would have been running fuel with an average cetane rating of 47. Not to mention to the other favors you would have done to your fuel system with a higher cetane rating. That being said, using a cetane improver like Hot Shot’s Secret Diesel Extreme or EDT every time you fuel up will pay for itself in more ways than one over the lifetime of a vehicle.