What is the difference between diesel and gasoline?

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When you fill up with fuel, it’s evident to power your car: Without this fuel, nothing runs. And what kind of fuel you need depends on your car’s engine. E-cars are rising, but two conventional fuel families dominate gasoline and diesel.

The classic: gasoline
Let’s start with gasoline. When we fill up a gasoline car, we have a choice of three types: Super 95 or E5, Super E10, Super Plus, and E85 or bioethanol.

What does the “E” stand for?
E5, E10, E85: These abbreviations have nothing to do with food additives. The “E” stands for… “ethanol.” Because yes, gasoline fuel contains ethanol, i.e., a biofuel.

The abbreviation specifies the proportion of biofuel in your gasoline. Example: E5 gasoline (also called Super 95) contains up to 5% ethanol of plant origin.

The octane rating
And why 95 and 98 now? These numbers correspond to the octane rating. Octane, also known as C8H18, is the main component of gasoline. The octane number determines how resistant the gas is too uncontrolled ignition.

The higher the octane number, the more protected the engine, and the less likely your car will catch on fire. Very simplified.

The new ones: E10 and E85
Since 2009 there is also E10. It contains up to 10% ethanol. E85, on the other hand, consists of up to 85% bioethanol.

And when we talk about bioethanol, we mean ethanol of plant origin. It doesn’t necessarily mean it’s organic, in the sense of organic quinoa or kiwi juice.

Gasoline vs. diesel
But what is the difference between gasoline and diesel?

First of all, there’s the composition. Both diesel and gasoline are composed of hydrocarbons, carbon, and hydrogen.

While gasoline contains mainly octane, diesel consists of much heavier hydrocarbons such as ketane, or C16H34 for short. And this difference is also reflected in the way engines work.

Different engines
A diesel engine injects fuel under very high pressure, resulting in high heat. The diesel fuel then ignites spontaneously.

In a gasoline engine, on the other hand, an air-fuel mixture is ignited by the spark plug.

Advantages and disadvantages of diesel and gasoline
This difference is often summarized as gasoline engines being better for regular short trips because they don’t have to heat up as much. But diesel engines usually have better efficiency.

So what happens when you put gasoline in a diesel engine or diesel in a gasoline engine? Well, at least nothing explodes. But: There is a risk of engine damage and an expensive stopover at the auto repair shop.