Yes, the combustion of fuel in cars is a chemical reaction. When fuel is burned, it reacts with oxygen from the air to produce carbon dioxide and water. This reaction releases energy in the form of heat and light, which is what powers the car engine.

The specific chemical reaction that takes place when fuel is burned is called combustion. Combustion is a type of exothermic chemical reaction, which means that it releases heat. In the case of fuel combustion, the heat released is used to power the car engine.

The overall chemical reaction for the combustion of fuel in cars can be represented as follows:

```

C8H18(liquid) + 12.5O2(g) -> 8CO2(g) + 9H2O(g) + Heat

```

In this reaction, octane (C8H18), which is a component of gasoline, reacts with oxygen (O2) from the air to produce carbon dioxide (CO2) and water (H2O). The heat released by this reaction is what powers the car engine.