Most, if not all motorists wish to cover a much longer distance on very little fuel. However, there are times when your car consumes a lot more fuel than the usual. This is attributed to a number of factors, mostly mechanical.
Old tyres and low tyre pressure
Take an example of Louis Katende, who, until recently, discovered that low tyre pressure or even tread-less tyres greatly impacts on fuel economy. He would not deliberately drive his Mitsubishi Pajero on low tyre pressure but the fact that the best tyres for his car come at a high cost of Shs800,000 per tyre, is something that always forced him to drive on old tyres for longer periods.
“I always thought that as long as any tyres (new or old) have pressure, it was okay to drive the car. When I asked the mechanic to inspect the car to find out if it had a fault that increased fuel consumption, he recommended that I change tyres and monitor fuel consumption patterns. After a week, I realised I was saving more money than I initially spent on fuel in a week,” Katende says.
Beyond just old tyres and low tyre pressure, you may also be wondering why your fuel consumption patterns differ from time to time.
Old or dirty air filter
According to Musa Kimera, a mechanic at CKK Garage in Wandegeya, fuel burnt in your car engine is supplemented with air sieved of dirt from the air filter. In the unfortunate event that your air filter is old or clogged with dirt, partly due to failure to replace or service it on time, it will mean that little or no air will be making it to the engine compartment to allow air mix with fuel. This, Kimera, cautions, means that your engine will do away with air and instead burn more fuel, hence increased consumption.
On average, a full tank of fuel for a Toyota Premio costs approximately Shs237,500 and this would take you from Rukungiri to Kampala.
However, when Robert Akampurira was returning from Rukungiri after the 2019 Christmas festivities, he had carried lots of foodstuff in the car trunk of his Premio that the rear part of the car appeared bent.
Instead of the usual Shs237,500, Akampurira recalls spending at least Shs250,000 on fuel because the boot was overloaded, requiring him to refuel at Lukaaya on his way back.
This, Kimera confirms that Akampurira’s engine automatically had to use a lot more fuel to carry the excess weight.“Overloading your car does not increase fuel consumption on the Toyota Premio alone.
It cuts across all car brands and models for as long as you load your car beyond the weight it was prescribed to carry by the manufacturer,” Kimera clarifies.
Poor quality spark plugs
Much as the primary role of spark plugs is to provide the spark to start your car engine, they also determine the rate at which your car consumes fuel. Like brake pads, Kimera adds that it is recommended to replace your spark plugs after covering 5,000km. Above this mileage, the engine starts misfiring, a situation where the engine skips one of the stages when it is running.
Joseph Makumbi, a long distance motorist, advises that if you have a habit of overtaking even in the city centre where it is unnecessary, it means you will be using more fuel to achieve your goal. This is in most cases accompanied with switching off and restarting the engine when driving in traffic jam.
“When you over accelerate to overtake, the engine will burn more fuel to allow you overtake because there will be no maintained driving speed. If you turn off your engine in traffic jam, it means the engine will be idle and will have to use more fuel to warm up and run normally upon restarting,” Makumbi explains.
Poor quality engine oil
Most motor vehicle manufacturers prescribe the type of oil to use in your engine. But because you may sometimes want to save money, you may ignorantly deviate from the manufacturer’s prescribed type and adventure to the oil type you think can also work.
“If you use engine oil that is thicker or lighter than what is recommended for your car, the engine pistons and other engine parts that rely on engine oil will not function at their optimal best. It means the engine will have to perform beyond its capacity and this will lead to increased fuel burn out,” says Allan Ssekamatte, a mechanic at Vine Auto Garage in Kisaasi.
Improper gear changes
According to Oards Automotive Hub, an online portal, improper gear changes is especially true with manual transmissions but also applies to automatics with sport modes.
“Do not change gears too early or too late. If you try to upshift at too low of an RPM, the engine has to work harder to accelerate,” the portal advises. RPM is the abbreviation for revolutions per minute.
The portal adds that alternatively, if you constantly let your engine run in the upper RPM range in your power band since you enjoy the extra power, keep in mind that you’re also burning a lot more fuel.
To realise better fuel economy, you may have to, among other things, ensure that your tyres always have the recommended tyre pressure, replace your engine oil every time you go for service, have a functional air filter and avoid overloading your car.
How to reduce fuel consumption
Drive only when needed. The best way to reduce the fuel consumption is to simply drive your car less. Drive your car only when you really need to. If you only need to travel a few blocks, consider walking or even riding a bicycle. Not only will you save money at the pump, the exercise will certainly do you some good
When you do need to drive your car, make sure you avoid idling whenever possible. When your car is running, but not moving, your fuel mileage is zero. So if your car will remain stationary for more than a minute or so, switch the engine off.
However, only do this when it is safe to do so
Accelerate and break steadily. While driving, always apply steady and consistent pressure to your car’s accelerator pedal. A heavy foot will always result in reduced gas mileage and poor fuel consumption
Drive the speed limit
Always try to drive at or near the speed limit. The optimal travelling speed for every make and model vehicle is different. However, the faster you drive, the worse your fuel mileage and fuel consumption will be.
Coast when possible. Constantly accelerating and braking only wastes fuel and reduces your car’s fuel consumption. So, whenever possible, coast and avoid burning excess fuel.
Keep the windows closed. Keeping your windows down while driving creates more drag and wind resistance for your car. If you are driving at speeds of less than 35 mph, it is usually okay to keep the windows down. However, at higher speeds, you should keep the windows up in order to reduce drag and improve fuel consumption.