Cars Becoming Less Fuel Efficient with Time
There is no denying, cars become less fuel-efficient with time. Although ageing parts can fail, a well-maintained car can keep up with the fuel economy. You cannot compare a model from the 1990s to the 2020s, as modern cars are designed aerodynamically with engine specs to suit fuel efficiency.
Let’s explore some of the reasons that cause an ageing car to become less fuel-efficient with time
Reasons for Less Fuel-Efficient Cars
Mechanical & electrical components of a vehicle don’t last forever, however, with a proper maintenance routine, you can definitely increase the likelihood of the engine. Failing engine components can lead to a list of numerous problems including reduced fuel efficiency.
Let’s delve a bit deeper on what components require regular inspection to maintain the fuel efficiency of an ageing car.
Fuel System

The fuel system is integral for proper engine operations. Problems with faulty fuel pumps or fuel injectors can dramatically impact the fuel economy. If the fuel system is unable to pump the proper amount of fuel, this will lead to an un-optimised air-fuel mixture in the engine.
For instance, running an engine on a rich fuel mixture will result in the worst fuel economy. As more fuel is wasted to generate engine power, it also creates more emissions.
On the other hand, running an engine of lean fuel mixture does not mean your car will be fuel-efficient as it can suffer from serious engine damage. Pre-ignition or engine knocking are prime causes of the lean mixture and due to the jerking motion of the engine, you can expect reduced car performance.
Air Filter
A clogged air filter can block the amount of air required for proper engine combustion. If the engine does not receive the right ratio of air, it can lead to improper combustion resulting in engine knocking and reduced fuel efficiency. This has a negative impact on overall power and acceleration.
Spark Plugs

Spark plugs are responsible for the timely ignition of the air-fuel mixture in the engine. Since the spark plugs wear out with time due to intense heat and pressure in the combustion chamber, you can expect reduced engine performance and weaker mileage.
Engine Oil
The engine oil creates is a defensive lubrication layer to protect engine components while being constantly exposed to heat and pressure. With time it becomes sludgy and unable to clean the engine efficiently. Hence, without proper lubrication, the engine tends to run hotter resulting in decreased horsepower and fuel mileage.
Exhaust System
The exhaust system of a car consists of oxygen sensors in the manifold. Based on the amount of oxygen in engine exhaust, the ECU can control fuel injectors to add more or less fuel accordingly.
If the exhaust system has a leak, specifically before the oxygen sensor, the sensor can predict the lack of oxygen and will inject more fuel to compensate for the lean mixture. Hence, the unwanted injection of fuel into the engine results in reduced fuel economy.
Tyre Pressure

There is a reason why modern cars are now equipped with tyre pressure sensors. Underinflated tyres tend to have more contact with the road, which results in increased friction and wear. Underinflated tyres require more force to roll, making the engine work harder and negatively affecting the fuel economy. If your tyres are worn and goes flat frequently, explore replacement options with used car tyres for sale in the UAE.
Frequently Asked Questions
Why do older cars consume more fuel?
Failing or faulty engine components are the prime reason for increased fuel consumption in older cars. In some cases, the design of the car can play an important role. For instance, modern cars are aerodynamically designed to reduce the impact of air resistance with lighter material for better fuel efficiency.
What causes high fuel consumption in cars?
High fuel consumption in cars can be due to faulty engine components or the user’s driving habit. If you witness high fuel consumption, get your car inspected for dirty air filter, oil change, exhaust leaks, worn out spark plug and under inflated tyres. You can also explore new and used auto accessories & parts for sale to find affordable replacements.
Although your cars become less fuel efficient with time, you can prolong fuel efficiency by conducting regular maintenance checks. Normally dashboard warning lights like engine check lights can alert you of failing symptoms.
Problems with the air filter and spark plugs can be easily managed on your own through inexpensive replacement. You can even change oil yourself provided you know the type of oil and change the oil filter as well.
However, if the problem lies in the engine such as leakage in the exhaust manifold or a faulty oxygen sensor, you may consult with your service centre or private workshop to get it fixed.
Vehicle components have a lifespan and can fail eventually. Older cars might require more frequent visits to service centres for replacement of faulty parts. If your car needs consistent maintenance inspection, you can explore your options with used cars for sale in the UAE.
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