Used Petrol Cars for Sale

A petrol engine requires a series of components to work in unison to run properly, and when they don’t is when problems emerge.

Simply put, combustion engines work when fuel is burnt and releases energy, which then mixes with air. This process happens within the engine itself. The engine itself is made up of a fixed cylinder and moving pistons, with the expanding combustion gases moving the piston, which then rotates the crankshaft. When linked through a gearbox, this helps to drive the car’s wheels.

Now, there are two types of internal combustion engines – spark-ignition petrol engines and compression-ignition diesel engines. In a petrol engine, the fuel is mixed with air and then enters the cylinders during the intake process. Once a piston comprises the fuel-air mixture, the spark ignites it, creating the combustion process.

There is a slight complexity in the fact there isn’t one type of petrol available in the UK, but rather three different types.

E10 is now the default petrol in the UK and has been since September 2021. The ‘E10’ stands for 10 per cent of the fuel mixture being ethanol, which helps to reduce emissions.

While all newer petrol cars can run on E10, if your vehicle is older, or a classic car, you are best off sticking with the more expensive ‘premium’ unleaded as the higher ethanol content may cause damage. If you’re unsure, you can check if your vehicle can run safely on E10 using the government’s eligibility checker (https://check-vehicle-compatibility-e10-petrol.service.gov.uk/).

There are several advantages of petrol engines, especially when compared to diesel. For starters, generally, petrol is cheaper to buy at the pumps, while it’s much better suited to shorter journeys and stop-start traffic than a diesel because they’re less likely to get clogged up.

Petrol engines generally produce fewer particulate emissions, which are a key contributor to local air pollution. It’s why an older petrol car is far more likely to be compliant with a low-emissions zone (such as London’s ULEZ) than an older diesel car.

While petrol cars might have lower particulate emissions, they tend to have higher carbon dioxide (CO2) emissions than diesel. This was (and remains on new cars on their first registration), how car tax rates were calculated, with cars with lower CO2 generally being cheaper to tax.

Petrol engines are also not as well-suited to longer trips, as they typically sit at higher revs than a diesel while also returning worse fuel economy. As a result, petrol engines typically wear out a little earlier than diesel, though maintenance plays an important part in this.