‘Dieselgate’ and the recent emissions scandal

Posted on September 23rd, 2015 by Rob Marshall


Rob Marshall has spent some time researching the inconsistencies of vehicle exhaust emissions and, while he is unsurprised at the current situation that is engulfing the Volkswagen Group in North America, he views the current media frenzy as being somewhat misdirected.

What is the background to the ‘crisis’?

To allow a vehicle to be sold in a particular market, it has to pass certain exhaust emissions regulations to gain conformity, or “Type Approval”. The technical details depend on the local regulations.

Volkswagen Group has admitted developing software, within certain diesel engine ECUs of cars sold in North America, to recognise when an official emissions’ test is being carried out. The engine then runs in a way that reduces the measured pollutants to give the best results under examination conditions. This would not happen under normal driving situations. This examination is a Type Approval test, carried out on a sample; not every single car is inspected.

One reason why the Volkswagen Group is facing a particular backlash across the pond is that the company’s advertising has focussed on Clean Diesel technology but the recent investigations have called both the claims and the company’s integrity into question. Although what has occurred is wrong, the authorities that have allowed the manipulation to be undetected for so long appear to be escaping scrutiny.

Does this mean that more pollutants are emitted in the real-world?

Yes. However, even in real-world testing, more modern engines tend to be less polluting, overall, than older ones, although this is not always the case. It is fair to comment that carmakers (including VW) have made considerable gains in reducing tailpipe emissions and optimising efficiency, overall.

Does this affect Europe and the UK?

At the time of writing, the answer is a definite ‘maybe’. Allegations about other manufacturers manipulating test vehicles to perform well in the Type Approval emission/fuel economy tests in Europe (and not just for diesel cars) have circulated for years.

However, proving foul-play is very difficult, maybe impossible, since many of the individually tested vehicles are likely to have been destroyed soon after leaving the laboratory. Yet, the Society of Motor Manufacturers and Traders (of which many UK-arms of car manufacturers are members) states…

“This is an issue affecting just one company and there is no evidence to suggest that any other company is involved, let alone that this is an industry-wide issue.”

We can only wait and see, to find out if any official investigations are carried out in Europe and what the results might be.

Are the tests outdated?

Yes. As they know the tests’ requirements, carmakers have also developed technologies that have more of an in-lab benefit, compared with the real-world, such as Stop-Start systems. The various Type-Approval tests are being modified, owing mainly to consumer complaints about laboratory-obtained fuel consumption figures not being attainable under real-life conditions, even though it has always been stated that they are for ‘guide purposes’. However, the authorities have been very slow to react to growing consumer anger about them experiencing increased running costs. Now it is too late, the unforeseen (but fairly obvious) increase in emissions is just being realised officially.

This was highlighted to me years ago, when I used to participate (as part of the winning team on several occasions) in real-world official fuel economy competitions. Many colleagues that drove supposedly ‘green’ hybrid petrol cars could not even attain their official combined fuel consumption figures. Ironically, the cars that used to beat their stated fuel figures by the widest margin tended to be higher performance, turbocharged vehicles, which made a mockery out of the entire exercise, until they were banned by the organiser.

The fact that North American and European fuel economy and emissions tests are recognised as being no longer representative of real-world driving is old news; modifications to the procedures are being mooted. Interestingly, certain carmakers are lobbying against proposed changes being made to the current European testing regime. However, legislators continue to be sluggish to implement revised methodology.

Will my car fail its MoT if the maker has been found to have committed wrongdoing during the type-approval test?

No. The MoT Test checks only for smoke opacity and does not consider more complex emissions, unlike the more thorough Type Approval tests.

Is this another death-knell for diesel?

Politicians might leap onto the bandwagon and use the developments to fuel the backlash against diesel. However, diesel engines still tend to be far more efficient than petrol ones; manufacturing (and scrapping/de-polluting) a diesel engine is also less energy and resource intensive than making a petrol hybrid, for example. Yet, the whole-life-cycle environmental impact of manufacturing both the car and its fuel is not considered by the legislators.

However, as we have stated before, some most modern direct-injection petrol engines have been found to produce over 1,000 times more soot than older, indirect injection designs. This may be due to other pollutants, considered during the Type Approval tests, being reduced to the cost of untested emissions going sky-high. Other issues about pollution emanating from plug-in hybrid engines also need evaluating in more detail, especially when maintaining catalytic converter efficiency can be very difficult in stop-start motoring. From what I have seen, legislators have still not reacted to those considerations.

Does aftermarket tuning offer a solution?

From my research performed thus far, the majority of engine ECU tuners invalidate the vehicle’s original Type Approval certification. In UK law, this can make the vehicle no longer road legal, even if it passes an MoT Test and, ultimately, the driver is liable, under the Road Traffic Act.

As most tuning systems (including remaps, tuning boxes and replacement chips) have not been tested for their impact on Type Approval tailpipe pollutants, emissions experts have told me that their use is likely to increase emitted pollutants considerably, even if fuel use reduces. No tuning company I contacted could (or would) provide evidence of independent exhaust emissions testing and/or compliance.

A further problem involves companies disabling anti-pollution systems in both cars and trucks, illegally, advertising their services openly without challenge. In the UK, funding cuts mean that the DVSA is checking only commercial vehicles for missing/modified anti-pollution systems, for the time being. Again, legislators are not ensuring that the law is being enforced.

What should be done?

There is no single solution and not one company/authority can be solely responsible. A joined-up approach is the only way to improve air quality, especially in our towns and cities. However, all measures must be proportional, considerate and not unfair to consumers that have been encouraged to buy certain vehicles in the past by misinformed policies. I hope that the following will be implemented:

  • At a local level, authorities should enforce existing laws, by stamping-out aftermarket modifications that render the vehicle unroadworthy, especially those that either increase tailpipe pollutants, or are untested. Independent tuning companies should also be encouraged to develop systems to play a role in developing properly-tested systems that can optimise an individual vehicle’s emissions.
  • National legislators need to ensure that their current outmoded, loophole-ridden emissions test methodologies are brought up to date. Thankfully, moves are in-place to do this but their effectiveness can only be evaluated long after they come into force.
  • On an international level, legislators need to consider the balanced views of motor industry and air quality experts, to establish whether, or not, either greenhouse gas emissions, or air quality, needs to be prioritised in the future. Currently, European taxation systems have focussed mainly on carbon dioxide emissions, possibly at the expense of air quality, and I have argued for many years that CO2 is the wrong measure.

Although I defend new car manufacturers rarely, they have been forced to meet ill-considered targets, in testing regimes that are outdated and vulnerable to corruption. While manipulating test results cannot be endorsed, it has highlight that the wider system requires a comprehensive overhaul. Rather than focusing their ire on carmakers, I hope that legislators and governments will realise that they are the real ones to blame and that any corrective measures must result in a cohesive plan that will make real differences to air quality, not just for media sound-bytes, but for all of our benefit.