There are many other factors that determine actual fuel efficiency achieved in practice, it is rarely possible to achieve the manufacturer quoted numbers, however, whenever the disparity becomes too wide, then a cause for concern is justified. We will quickly examine the commonest factors that determine fuel efficiency.
The first and most fundamental determinant of fuel consumption in cars is the engine size measured by its displacement. This is very popularly used by a lot of manufacturers as part of the vehicle model name. Examples abound, a few are Rover 1600, Datsun 120Y, Mercedes 230, BMW 316 etc, where these mean Rover 1.6L, Datsun 1.2L, MB 2.3L and 3 series 1.6L engine. Generally, the bigger the engine displacement, the thirstier the engine and the lower the number of kilos or miles you can drive on a litre of fuel.
The impact of engine size would be easily appreciated if under test conditions you could start a car engine, leave it stationary and let it run till the tank becomes empty. A fairly similar real life situation to this is driving in standstill traffic. On some of the inexplicable logjams we had on third mainly in 2006/2007 when it took an average of 6hrs to cross the bridge, drivers of very large engines will notice their fuel gauges moving towards empty right before their very eyes while the car was stationary and running their engines. Our tip here is to select your car based on need and proper information, don’t just buy the biggest engine you can find. This is why many manufacturers especially the German ones offer a very broad range of engines for the same car body e.g. MB offers engines for the C-Class from 1.8L to 6.3L, or BMW 3 series from 1.6L to 3.5L so you can chose the one that suits your need and your pocket. If you observe our ModelFactSheet data carefully you will be able to form consumption bands for various cars and brands just from engine sizes.
The second most important factor in fuel consumption is not the use of the Air conditioner or other engine mounted peripheral but driving style. Any driving style that constantly keeps the engine in high revs with very intermittent sharp acceleration and sharp braking will consume much more than driving in a smooth and silky manner. Taxi drivers in almost every city in Nigeria are very aware of this and many especially those up country where the taxis typically have no functional fuel gauges have developed a very heightened sense of monitoring and managing their fuel consumption. If you ever take a cab in what I call small-town-Nigeria, pay attention to how the cabby drives. I recall that many cars made in the 80s, especially Toyotas and Nissans had economy indicators, if you wanted the best economy figures in those models, you drove in a manner that kept the indicator perpetually green. Sadly, such indicators were removed from cars and not all cars have trip computers which was used to replace the indicators. However if you have a car that is equipped with trip computer and most new ones are, VW Golf, Passat, Toyota Corollas, keep your eyes on the trip computer, the better your driving style for fuel efficiency the higher the range the computer will be displaying. So there you have it, you may achieve significant reduction in fuel consumption if you stop imitating World Rally Championship (WRC) drivers on your way to work or home.
Other factors which influence fuel efficiency include, loading, some tunning work or car modifications including fitting fatter tyres than specified, some types of spoilers, air conditioners in small cars, driving with your windows down in people carriers and large SUVs, mechanical defects such as smoking engines, (Smoking is bad for your health in more ways than 1), exhaust leakages, and bad catalytic converters etc.
Based on manufacturers figures, the three most fuel efficient cars on Nigerian roads currently are the sibling duo of Kia Picanto and Hyundai i10, both running a 1.0L four-pot engine with manufacturer figures of 23.8 KPL. The Suzuki Alto also running a 1.0L four-pot engine rated by the manufacturer at 23.3KPL. , the Peugeot 208 also with a four cylinder 1.2L engine rated to achieve 21.9 KPL by the car maker. For other high fliers in the fuel sipping championship, see our current mPC-top10.
The proper interpretation of these figures is that with one liter of fuel you will drive 23.8, 23.3 and 21.9 kilos in the four cars respectively. In subsequent treatments of this subject, we will carry out actual tests to verify these claims and let you know. At a later point in time, we will reveal the 3 most fuel efficient cars in the most popular car categories in Nigeria. Note, our model info is very rich in fuel consumption data on the most common cars in Nigeria. Our database is expressed in Kilometer per liter (KPL) and we also feature a converter in our Utilities section to help convert miles per gallon MPG into the KPL used in this review