Avatar photo

By Mark Jones

Road Test Editor


Our long term VW Golf GTD produces brilliant fuel usage figures

Plan is to curb the manufacturers from manipulating outcome of a laboratory test.


Our long-term Volkswagen Golf 7.5 GTD is fast approaching the 12 000km mark without missing a beat and it has been an absolute pleasure to drive to boot.

.

And by drive, I don’t just mean racing against the clock and tackling mountain passes.

I mean more from an everyday power versus fuel usage point of view.

Which would likely be of more interest to somebody who opts for a diesel-powered car.

The people that build small capacity, naturally aspirated powered cars argue that their offerings are by far the better option compared to turbodiesel or turbo petrol powered alternatives.

And in my years of road testing, I can confirm they are right in some ways, but wrong in others.

Yes, their small capacity cars can achieve great fuel consumption, but this is almost always at the expense of performance, especially up on the Reef, where the air is thin, and their cars lose power and start to battle against their force-induced competition.

.

This is where our GTD excels the most in my opinion.

This hot hatch runs VW’s tried and tested 2.0-litre 130kW/350Nm turbodiesel powerplant mated to a sixspeed DSG transmission, and as already reported on, it has plenty of urge and not at the expense of fuel consumption.

To date, the GTD has consumed less than 7.0-litres per 100km of 50ppm diesel since we got it in April this year.

I did do an open road round trip of over 400km recently and setting the active speed control at the various speed limits as prescribed along the way, the GTD averaged an exceptional 4.8-litres per 100km.

These are not bad fuel consumption numbers, especially considering you would need quite a lot more horsepower than is offered by the average small naturally aspirated car to stick with the GTD.

But the overall average number of 6.97-litres per 100km is a bit more than the claimed NEDC number of 5.30-litres per 100km.

.

And this is why many new owners clash with their dealers – because they expect to get the claimed average or at least close to it and they just can’t.

Implementing the NEDC

The New European Driving Cycle is the test that must be used by new vehicle manufacturers/importers in Europe to determine the fuel consumption and carbon dioxide emission level of a new vehicle.

It was designed in the 1980s, and was used for the first time in 1990s, over 20 years ago, and it is done in a laboratory under strictly controlled conditions.

Here is one of the first disconnects.

.

This test is hardly a true reflection of how you drive in the real world today, a world that now many years later, has more traffic, higher speed limits and millions of company people who are given fuel as a job perk and are therefore not as concerned about fuel consumption or carbon di-oxide emissions as perhaps they should be.

What does this mean to you?

So, despite how it is claimed, you should know that you are going to be paying around R17 (at current prices) per litre of petrol or diesel more for every 1.0-litre per 100km your new vehicle does not achieve as per the NEDC test.

And there is nothing you can do about it, because our government only uses the carbon dioxide number from the NEDC test to tax new vehicle buyers.

A double financial blow for you and me, the everyday motorist.

.

Do we really care?

I don’t think we care nearly as much as we possibly should for obvious reasons.

We live in South Africa and it’s a tough place, with crime, corruption and the likes being more front of mind than how much carbon dioxide your car spews out.

Also, this tax is only levied on new cars as second-hand cars are exempt.

It is levied once only at purchase and not annually as in some other countries and is included and financed in the purchase of the car, so you don’t really feel the financial consequence of buying a gas guzzler.

.

Will there be change?

It is said the NEDC will be replaced by the a more modern standard WLTP (Worldwide Harmonised Light Vehicles Test Procedures) in the next year or so.

This test will measure higher average speeds and greater variations in speed and more strict test procedures will be applied.

But like the NEDC, the WLTP cycle is also measured on a test bench and this means it still does not take into account individual driving styles, weather conditions and unforeseen traffic conditions.

So it’s still not perfect, but it’s a little more realistic and it is expected that the increase in claimed fuel consumption values should go up by about 15 to 20%.

Slightly more complicated is that a method has been developed for introducing the WLTP into carbon dioxide legislation, which provides for converting WLTP measurements back to NEDC values.

I guess this means the carbon dioxide tax you are paying will hopefully not suddenly increase.

.

Will it get real?

WLTP laboratory measurements will in future be supplemented by the RDE test (Real Driving Emissions), which will measure vehicle pollutant emissions on the road for the first time.

Unlike the laboratory tests, the RDE test does not require compliance with any fixed driving cycle.

The RDE test will be conducted under whatever environmental condition exists at the time.

Acceleration, outside temperature, wind conditions and traffic situations will be as random as in reality.

The intention behind this additional test in future is to reduce the differences between the laboratory and real-world car use.

The plan is also to stop manufacturers manipulating the outcome of a laboratory test by using software that detects the test bench situation. For the RDE test, vehicles will be equipped with so-called PEMS technology (Portable Emissions Measurement System) for mobile emissions measurement.

PEMS is already used as standard for commercial vehicles.

So in the future we will be given a more realistic idea of the fuel consumption to expect from our vehicle and how much harmful gases it’s releasing at the same time.

This said, I am very happy to be driving a VW Golf 7.5 GTD because it offers performance and decent fuel consumption at the same time.

In the next update in January, our Motoring Editor will describe his experience with the GTD over the December holidays.

Log Book

  • Odo reading start: 1 046 km
  • Odo reading now: 11 948 km
  • Distance covered: 10 902 km
  • Fuel consumed: 759.39 litres
  • Total fuel cost: R11 550.48
  • Ave consumption: 6,97l/100km
  • Ave cost/km: R1.06

For more news your way, download The Citizen’s app for iOS and Android.

Read more on these topics

Golf Road Tests Volkswagen(VW)

Access premium news and stories

Access to the top content, vouchers and other member only benefits