The great fuel consumption swindle
‘Official’ fuel figures are one of the biggest cons in motoring
WHEN petrol and diesel were relatively cheap, many of us were happy to drive cars that burned 14 litres per 100km.
But now that petrol costs around R14 a litre, the need for fuel-efficient cars is greater than ever.
That is why the fuel economy of cars is such a selling point. And why manufacturers set such store by producing vehicles that are supposedly able to travel enormous distances on teaspoons of fuel. Claims are regularly made for cars that can run on 3.5 or even three litres per 100km.
But how accurate are these figures? The answer is not very accurate at all. In fact, the ‘official’ figures handed out as gospel by the car manufacturers are one of the biggest cons in motoring.
Last week, research by Emissions Analytics, a vehicle data company based in the UK, found that cars on average use 18 percent more fuel than is advertised.
And that’s just the average. The really bad news is that if you have a small car with an engine size of less than one litre, then your fuel consumption is a staggering 36 percent higher than the manufacturers’ claims.
Most small cars claim fuel-consumption of less than five litres per 100km, but the true figure is closer to 7.3 litres per 100km.
As the engine sizes get bigger, the discrepancy lessens. With cars of engines of two to three litres, the difference is about 15 percent, which is still significant. But that does mean if you drive a luxury ‘gas-guzzler’, the gap between its supposed and actual fuel economy is likely to be much less than if you’re driving a cheap supermini.
The great fuel-consumption swindle becomes even more alarming when you look at how these figures have an impact upon your wallet. Let’s say you are the proud owner of a Toyota Yaris Hybrid, which has an official fuel-consumption of 3.7 litres per 100km and you drive about 15 000km a year, mainly around town, doing the shopping and the school run.
Using the official fuel-consumption figures - and that may well be the main reason you bought the car - then you would expect to be using about 550 litres of fuel per year, costing around R7700. However, the true fuel-consumption for that model being driven around town is almost exactly five litres per 100km, which means that your real fuel cost will be R10 500 - an extra R2800.
So why are there such discrepancies, and how do car manufacturers get away with it?
The heart of the deceit lies in the European Union’s vehicle testing centres. For the past 40 years, the EU has subjected all makes of car to the New European Driving Cycle test, or NEDC for short.
One drawback with the NEDC is that it is anything but new - in fact, it is hopelessly out of date.
“There are two major problems with the test,” said Nick Molden of Emissions Analytics. “First, it is too gentle on cars and doesn’t replicate the real world. And secondly, there are too many grey areas in the way the tests can be conducted - areas that manufacturers are all too willing to exploit in a perfectly legal manner.”
The NEDC is indeed unlike the type of driving most of us are used to. The test is split into different parts. In the ‘Urban Drive Cycle’, during which the car reaches 50km/h on four separate occasions, manufacturers are given a full 26 seconds to reach that speed.
Molden says this is utterly unrealistic - most of us reach that speed within five seconds.
“If you try accelerating that slowly in a real situation, it’s almost physically impossible,” he explained.
During the fifth and final part of the test - the ‘Extra-Urban Cycle’ - the car reaches 120km/h. But it only has to remain at that speed for a few seconds. The point is that most people drive for considerably longer than a few seconds at about 120km/h when they’re on a freeway or national road.
To make matters still more absurd, the car is allowed to be stationary for a fifth of the entire length of test even though few of us, even in traffic jams, spend that long with the engine idling.
The test therefore gives a skewed picture of a car’s true fuel economy in everyday driving conditions.
Manufacturers are allowed to carry out all sorts of tricks to boost their cars’ performance, some of which beggar belief. In order to im- prove aerodynamics, manufacturers are permitted by the EU to tape up all the cracks around the doors and windows. This reduces drag and makes the car more fuel efficient than in real life.
Then aerodynamic tests - which measure the ‘inertia’ of the car - are carried out on a normal outside test track. But a special ‘rolling road’ is used in the fuel-consumption tests under lab conditions, and its rollers are adjusted to take account of the car’s ‘inertia’ measurements.
Brake pads are minutely adjusted in order to remove the slightest modicum of resistance on the wheels - resistance that is permanently there on a normal car.
According to a devastating report published by the Brusselsbased pressure group, Transport & Environment, the manufacturers also use special lubricants to ensure that engines run more efficiently than they would in normal use.
In addition, during most tests the alternator, which recharges the battery while the engine is running, is disconnected so the car uses less energy than in real life.
The engine is also specially tuned, the car is kept in fifth gear for most of the test and the weight of the car is kept to a minimum. Extras such as air conditioning and radios are removed, and even the passenger’s side wing mirror is taken off.
But that’s not the end of the trickery. According to the EU regulations, the test centres must be kept at an ambient temperature of 20-30 degrees. Because cars run more efficiently in high temperatures, the centres are kept at - you guessed it - 29 degrees.
This is farcical, as the average temperature in the EU is below 10 degrees. It also ignores the fact that for many people in Europe, cars are often run at low temperatures for several minutes during those cold starts in the winter.
And there’s another bizarre anomaly with the test centres, which almost seems impossible to believe. The regulations stipulate that no slope on the test track can exceed a gradient of 1.5 percent, so inevitably the motor manufacturers have all ensured the test tracks have this exact gradient built in. This means that the cars are tested for fuel efficiency as they drive... downhill!
In the eyes of transport experts, the organisation most to blame for this ridiculous system is the EU, which oversees a system that has no bearing on the real world.
Malcolm Fergusson, the principal author of the Transport & Environment report, is damning.
“Lax testing procedures are allowing car makers to manipulate the official tests,” he writes.
And it’s not just the fuel-consumption figures that are being fudged, he says, but also the levels of carbon dioxide emissions.
The system is essentially a joke, and the victims are the public, who are conned into buying cars with official figures that are essentially lies. Although a new system is being promised, that is not due for another six years, perhaps longer.
For the time being, car buyers need to keep a hawk eye on the real figures - and one place to find them is on the What Car? website, which carries data on 500 cars from Emissions Analytics.
The difference they show between the claim and the reality should make car manufacturers hang their heads in shame. But don’t hold your breath. FOR EXAMPLE: Ford Focus 1.6 Claimed fuel consumption: 6.0 litres per 100km
True fuel consumption: 10.3 litres/100km
Claimed fuel cost at 15 000km a year: R12 600 Actual fuel cost: R21 630 Difference: R9030 - Daily Mail
Editor’s note: As a publication in the business of road testing vehicles, our own experience concurs that actual fuel consumption figures are always higher - sometimes vastly - than manufacturers' claims. For this reason we make a point of listing both the claimed and actual figures in our articles to give our readers the full picture.
- Denis Droppa