Fuel is an essential part of transport, and there’s no avoiding it, despite how much we may want to when prices increase.

Fuel efficiency is something largely overlooked by drivers, who are under the impression that it’s their car’s job to be efficient. But your car can only work with what you give it. It’s best to know as much as you can about fuel consumption to ensure you own an efficient vehicle, you’re driving efficiently, and you’re checking for the right warning signs when filling up or maintaining your beloved car.

The surprising fact that fuel takes up 40% of your car’s running cost means we should care about fuel efficiency. The price of fuel affects everyone, but there’s not much we can do about what fuel costs. But, we can do something about how efficiently our cars use that fuel. 

In short, we measure fuel consumption by calculating how many litres of fuel is consumed for every 100km driven. You don’t need to get a mechanic or your local dealer to test this for you, and while your manufacturer’s guidelines should offer an expected fuel consumption, you can test this for yourself by following these steps:

1. Fill up your car to a full tank.
2. Zero your trip meter.
3. Drive your car like you normally do for a considerable distance e. 200 - 300km.
4. Fill up your tank to a noticeable stop.
5. Divide the distance travelled by the litres used and you will get the km/litre.
6. Convert km/litre to L/100km (i.e. divide 100 by km/litre).
7. You now have your fuel consumption rate, which is always recorded as L/100km.

For the Suzuki Swift, this calculation may look as follows:

• Filled up tank with 22.4 litres. 
• Travelled 400km.
• 400/22.4 = 17.86km/l
• 100 / 17.86 = 5.6 litres / 100km

Your car’s manufacturer publishes average fuel consumption figures regularly, which they arrive at through considered testing (in different driving cycles, conditions and temperatures) to work out a trustworthy average fuel consumption per vehicle model. This is why the manufacturer’s published figure is always a good indication of a car’s fuel efficiency, but it’s never set in stone and can still be influenced by a variety of factors.

Ten factors that Affect Fuel Efficiency

1. Engine size
   It’s a simple fact that bigger engines use more fuel.
2. Vehicle size and weight
   Again, put simply, a heavier car uses more fuel to carry itself. 
3. Maintenance
   Keeping your car in tip-top shape is important to maintaining fuel efficiency, because when upkeep is neglected, everything runs less efficiently, which usually results in a loss of fuel efficiency. 
4. Tyre pressure
   Worn out or flat tyres pull your car out of alignment, which causes additional friction to your car’s momentum and directly influences its fuel consumption.
5. Aerodynamics 
   While this always impacts fuel used, it mostly has a role when you’re doing long distance travelling. Less aerodynamic vehicles, like vans or SUVs, will experience more wind resistance, which, like tyre pressure, acts as additional friction and forces your car to use more fuel for the same speed otherwise. 
6. Turbos 
   Turbos are surprisingly good for fuel efficiency, against popular opinion. It’s a power-smart and fuel-smart choice. Turbocharged engines differ from naturally aspirated engines in that turbocharged engines artificially pump more air and fuel into the engine's combustion chambers, whereas naturally aspirated engines use natural air pressure to trigger combustion. This can help smaller engines produce more power. This means that you can achieve similar power to larger engines in smaller cars, avoiding the need to install big engines that guzzle fuel in many instances. This is just one of the reasons that Suzuki has introduced turbos to two of our models. 
7. Distance
   You’ll have often heard the adage that “regular short trips aren’t good for cars” and one of the reasons for this is because it guzzles your fuel. Your engine works best when it’s warmed up, and short trips simply don’t allow it enough time to do so, making your car use more fuel for the same results in long-distance travelling. 
8. Drive style
   This goes without saying, but speeding, excessive or hard braking, and other bad driving habits or styles all impact your fuel consumption negatively. Like with most of the previous points, if you’re making your car experience more friction and weight, or regularly using more power than is necessary, you’re wasting fuel.
9. Oil
   Motor oil lubricates your engine and so reduces the friction your engine experiences while running. The better lubricated your engine is, the easier it will run without friction, and the less fuel it’ll need to do so. 
   
   

If you’re interested in finding out how fuel efficient your car is, use this handy fuel efficiency tool to work it out.

How Does Your Car Compare?

With ever-increasing fuel costs, getting a fuel-efficient car is more important than ever. But how do you know if the car you’re interested in, or the car you own, is fuel efficient? Perhaps you’ve worked out the L/100km… but now what? Is there a standard? What does this tell you, and how do you use this information to your advantage?  

Off the bat, if you find your L/100km is a lot higher than your manufacturer’s average, you need to get your car looked at. While not everyone might experience the manufacturer’s average exactly, it’s a trustworthy figure that should guide you in deciding how efficient your car is. There are many things that could be pushing consumption up (see our list in the previous section of this post), but big differences usually mean bigger reasons (i.e. a mechanical problem).  

Compare like for like:

While the first port of call is to compare your car’s fuel consumption against the manufacturer guidelines, if you’re trying to understand how efficient your car is in the greater scheme of things… compare like for like. It’s no use comparing your SUV-style Suzuki Vitara with the statistics of the compact Swift – these models aren’t comparable. All manufacturers will display fuel consumption figures for their vehicles, which is fairly easy to find. You will often find three published figures:

1. City/town driving (the highest figure per 100km).
2. Highway/open road driving (the lowest figure per 100km).
3. Average/mixed/combination (an average between the previous two figures).

The main figure to use when comparing like-for-like is the average/mixed/combination fuel consumption (as this is most commonly the closest figure to what you will experience). When wanting to check your car’s consumption, compare it with that of other, similar vehicles. Only compare cars of similar size, weight and engine capacity. Bigger isn’t always better, as bigger cars are less fuel efficient than smaller cars. This is mostly due to the cars weight and engine sizes – bigger cars like SUVs are a lot heavier and have larger engines that need more fuel to run than smaller cars, like the Suzuki Swift or S-Presso. 

But, no matter your car’s size, there are certain tricks that you can take advantage of to ensure the best fuel consumption for those longer trips.

Fuel is usually a grudge purchase, even though it’s one that most of us depend on. A lot of factors go into the price of fuel, as you can see from the image below, and when we start to understand all these factors, the pricing makes a little bit more sense.

But even understanding how the price of fuel is put together doesn’t give drivers a good idea on how to budget for their monthly fuel necessarily. To do that, you need to understand four key things, which are specific to your and your car:

• Which fuel your car uses

Did you know that fuel affects your car’s performance? The right fuel lubricates your engine, while the wrong fuel can lead to knocking (which isn’t a pleasant experience for both car and driver). Be sure you know if you’re filling up with 93 octane, 95 octane or diesel… or if your car is electric! You can find out which fuel your car needs in your handbook.  

• The price per litre 

Every fuel sold is sold at a particular price per litre. Understanding the price of fuel in South Africa is a bit confusing: the price is made up of a base fuel price, a fuel levy, a RAF levy, service cost recoveries, wholesale margin, dealers margin, storage and handling costs, and the final distribution costs... and still some geographic specific levies (i.e. the inland demand levy). However, there is not much that drivers can do to influence the price of fuel, other than purchase fuel-efficient cars. You can find the latest fuel prices on the AA’s website. 

• Your car’s fuel efficiency 

This is usually worked out to how many litres of fuel you use per 100km. Work out your fuel consumption here.

• How much driving you do in a month

Don’t be too nit-picky here… take an average. The best would be to record how much you drive over a month or two and use those figures. If you plan on a long distance trip one month in particular, you can then add this distance on for that month.

Once you can answer these four questions then it's a matter of using some basic maths to work out what your monthly fuel budget should be. Divide your monthly average driving distance by 100, then multiply this by how many litres you used per 100km, and finally multiply this by the price per litre of your car’s specific fuel. The number that you’re left with is the likely budget you will need to keep driving each month.

Does your local petrol station owner control the price of fuel? Can you switch petrol stations regularly? Does the quality differ at different providers, and how does switching between each affect your car? These are the questions that many drivers wonder as they pull into a petrol station, with no way of knowing the answer until it’s too late. Until now. There are many petrol station myths floating around South Africa, some of which have a bit of truth within them, while others are certainly incorrect. Understanding which ones you can trust might just save you on maintenance this year. 

Fuel is the same at all petrol stations

Myth. In South Africa, our fuel is standardised by the National Energy Regulator of South Africa, who is responsible for regulating the petroleum pipelines industry in accordance with the Petroleum Pipelines Act, 2003 (Act No. 60 of 2003). So there’s a standard that ensures the base of all fuel brands are the same, but every brand will still add their own mix of additives into their particular fuel. In short, fuel brands are never the same.

Refuelling your car while it’s running is dangerous

Fact. No, your car won’t explode necessarily, but that could happen. Refuelling your car while it’s running not only damages your car (your car’s vapour recovery may be damaged, as harmful vapours are released when you fill up), but it can also take only a drop of petrol for the engine, exhaust tailpipe or catalytic converter to catch alight.

Pump your own fuel if there’s no attendant

Myth. While pumping your own fuel might be the case for countries like the USA, UK, France and Spain, it’s not the case in South Africa. In fact, it’s illegal to self-serve yourself at a petrol station in SA. The reasons for this are various, but they mostly revolve around health and safety. When you next have the inkling to self-serve yourself, rather wait for the trained attendant, who understands the risks and warnings involved in dealing with fuel.

Petrol pumps are not accurate

Myth. Petrol pumps are accurate, although there can be mistakes made. If you want to ensure you’re accurately paying for what you get, then always ensure the pump board display reading is set at ZERO. You’ll also want to double check that the attendant fills up your car with the correct fuel, as using the wrong fuel (or oil) can be disastrous. Get out of your vehicle if you can while the attendant fills up your tank.

Filling station owners control the petrol price

Myth. As we’ve mentioned earlier in this post, the price of petrol is controlled through a number of systems and key players, but the idea that filling station owners play a role in petrol hikes is false. The petrol retail price is regulated by the government, and the calculation of the new price is done by the Central Energy Fund (CEF) on behalf of the Department of Minerals and Energy (DME).