The Sunday News
Lovert Mafukure
While the fuel price has been going down, it is still a bit more expensive compared to other countries, anyone of us would appreciate a drop of fuel to take them the extra mile. A lot of gadgets have been developed that are supposed to save fuel but none of them so far have proven to put the mind at ease when it comes to lowering fuel consumption. Oftentimes it all boils down to simple routines that most people overlook.
Here are some fuel saving tips:
Servicing your car regularly helps save fuel. For a car to run you need oxygen, fuel and spark for ignition. For diesel engines, you do not need the spark but well, this is not a science lesson. For maximum engine efficiency, you need the right amount of each of these at the right time. Otherwise, you will have decreased fuel economy and consequently a less efficient engine. A good flow of air (oxygen) is important and that is why you need to keep your air filter clean. They get dirty and clog up overtime.
Reduced airflow means you will start burning too much fuel for oxygen available. The mixture will be too rich and the result is incomplete combustion. The overall result is wasted fuel and loss of power — the irony of it all — more fuel less power, which is not what we want.
It should be the other way round, more fuel more power but well . . . That is why you need to service your car regularly. If you use dust roads a lot, you may need to do more cleaning or changing of filters regularly.
Newer cars have mass airflow meters or sensors, they measure the airflow to provide the right amount of air at the right time every time. These also get dirty and at times need cleaning or replacement. Routine checks can help you increase your fuel mileage. At times a faulty or dirty meter can cause rough idle and general poor performance and ultimately your car will use more fuel than normal. You need to keep them in check.
Spark plugs on the other hand fire as many more times than you breathe in and out and they suffer from wear and tear like everything else on earth. Sometimes they get dirty and need cleaning. A dirty or worn plug will cause a car to misfire. A misfiring engine will hit your pocket hard due to the increased fuel consumption. It is wise to replace these or clean at regular intervals. Your wallet will thank you. Imagine if you can save a thousand dollars on fuel in a year. In this economy, it is worth it.
Tyres are also a very important part of a vehicle. It’s important to keep the correct air pressure every time. It helps reduce your fuel bill and helps increase the life of your tyres. Every car has different tyre pressure inflation. Usually you find this information on the driver’s door. The side of the tyre has the maximum air pressure recommended for that tyre but it’s not always the correct level.
People tend to overlook the fuel cap. Sometimes people lose these and put just a lid to cover or sometimes a plastic. Petrol evaporates quickly and the fuel tank needs to be airtight. If it’s not, you may good and well be wasting your money for petrol to evaporate right out of your tank.
In a recent article, I mentioned the superiority of a manual transmission over an automatic where fuel efficiency is concerned.
Older automatic transmissions use more fuel per kilometre than manuals. I refer to older automatic cars as they are the majority on our roads — cars from the 90s. This is so usually because of a whole lot of reasons. They are heavy, they require more power to change gears and usually have less gears than manuals. Usually they come with three speed gearboxes and a fourth gear as overdrive. Manual transmissions usually have five forward gears going up. If you are going to settle for newer cars then it may be a different story, newer automatics have up to eight gears and will do some justice to your pocket especially on highway driving.
Driving style also affects gas mileage. An aggressive style of driving with rapid acceleration and braking wastes fuel. A gradual acceleration not only increases engine life, it will save on fuel too. Speeding generally takes its toll on your fuel consumption.
Most cars reach optimal fuel efficiency between 50 and 80km/hr. Optimum speeds vary with different vehicles. However, one will notice more fuel consumption when travelling over this optimum speed. A car uses more fuel as the speed increases.
Some researchers note that at 120km/hr a motor vehicle uses 20% more fuel than it does at 100km/hr. The percentage increases as the speed increases and it is quite significant.
A personal experience has proven this to me. I once embarked on a road trip of about 800km on a single tank during the day maintaining speed limit averaging 110/hr with a rev count of around 2-2 500rpm. The return trip cost me almost two tanks of fuel for one reason, I was wilding out above the speed limit with engine speed playing around 5 000rpm. The difference is huge. If I had maintained speed limit I would have saved almost a full tank of fuel but because the engine was racing that high, it took its toll and full tank went right out the exhaust. Sometimes I think the government puts speed limits so we don’t overspend on fuel . . . food for thought. The idea is to keep the engine revs down, as a car owner; you will slowly learn the optimum speed for your car and save tonnes of money per month or year as you cut down on fuel consumption.
Still on driving styles, we learn at the driving school how to “change-down” when coming to a stop. It is using the engine power to bring the car to a stop or to reduce speed. One would notice as you change down a gear the engine RPM go up while the car slows down. That is fuel being burnt; sometimes you need know and plan your journey before hand, even if it is just going round the corner. Sometimes putting the car in neutral and letting it glide to a stop saves you some fuel by taking advantage of the momentum you have built already while driving. The change-down trick is the same recommended by manufacturers for automatic transmissions. First, you switch overdrive off then it will kick down to third gear, you will notice the engine rpm change up as the speed decreases then you go to Drive 2 and so on. Whether its auto or manual it’s still wastes a bit of fuel doing that. While putting a car in neutral leaves you with less control, it leaves you with more fuel. Always take extra care therefore.
Most of us think that idling does not use that much fuel but if ever you’ve found yourself stuck on the roadside out of fuel then you know that every drop of that precious liquid counts. City driving with a lot of start and go traffic chews too much on your fuel; it’s wiser to use less congested roads. Manufacturers have started manufacturing cars that completely shut down when the engine is supposed to idle, it starts up again in real time as you press the accelerator without having to start the car again . . . clever? Well, wait until the cars start flying.
Lastly, always aim at travelling light; remove unnecessary things that add weight to your car. More weight simply means you car will work harder to avail the required power to haul your consignment. Roof racks, opening windows, sunroofs at highway speeds also add a little to your fuel bill. All these create drag and the engine will again have to work harder wasting fuel at the same time. Closing all windows and using air-con has been proven to actually save on fuel because it does not affect the aerodynamics of a motor vehicle in any way. So let’s save on fuel and maybe the environment too . . . so sometimes the best bang for your buck is not a hybrid car or an electric car but a simple routine that saves fuel.
Lovert Mafukure is a Japanese Imports consultant. For comments or questions regarding all Japanese imports and all Japanese motoring concerns. You can contact him on Whatsapp/SMS +263772339938 or email [email protected]
