Last reviewed 20 May 2015

Few people need convincing that we should cut pollution; most of the discussion focuses on ”how” rather than ”why” or ”if”. In fairness, there are still some who don’t accept the evidence for a link between pollution and climate change, but most of these people seem to agree that man-made pollution is unpleasant and probably avoidable, as Robin Dickeson reports in this article.


Worries about vehicle emissions have been with us for nearly as long as the automotive industry. But we had to wait until the 1960s, when California introduced the first vehicle emission laws in an attempt to tackle Los Angeles’ smog. Those Californian laws were sufficiently successful to encourage others to try similar ideas. This started a process that has led to increasingly tough emission restrictions around the world and had a dramatic and long-term effect on vehicle and engine design and development.

Leave it to the manufacturers

There is also a far-reaching and widely-held perception that vehicle makers should be the people to tackle emissions. By implication, this meant that legislators could set an environmental performance target and leave its implementation to the vehicle makers. The public, voters, need to do little more than buy the latest vehicles.

Broadly, the better developed a country, the tougher and more effective its anti-pollution laws and their enforcement.

Latterly, the various regulators around the world have started to talk to each other and most are working toward consistent and harmonised rules worldwide. This is vital for vehicle makers, who struggle to cut development costs while coping with different emission demands from different but sometimes neighbouring markets. It is also important for international operators.

The ideal is a set of internationally agreed and applied emission standards to which vehicles can conform and be sold and legally operated anywhere in the world. That is probably some time away, but more and more countries are moving in the same direction.

European emission standards set

In Europe, developments have taken us through a series of increasingly tough emission standards, starting at ”Euro I”, published in 1991 and effective from 1993. Euro I significantly cut the allowable limits for carbon monoxide, hydrocarbons, particulates (microscopic pieces of soot) and oxides of nitrogen.

Successive Euro levels have cut truck and bus emission limits further. The latest, Euro VI, took effect in 2014 and brings with it a range of additional engine control systems and complexity. Euro VII is still officially an unknown quantity, as it is unlikely to be introduced until 2020, as part of another round of emission standard changes. That process seems likely to regulate automotive carbon dioxide (CO²) emissions for the first time. If that is the case, it will have taken us nearly 60 years from those first emission laws to get around to mandatory limits on CO² emissions.

If we get Euro VII and then perhaps Euro VIII and beyond, operators can expect each successive standard to be tougher and more wide-ranging than its predecessor.

In the meantime, there is widespread worry about local municipal emissions regulations across Europe and further afield. London’s Low Emission Zone (LEZ) is a good example. Local and regional Air Quality Action Plans across the EU mean that many cities have developed and now enforce their own LEZs. Fortunately, those within the EU are reasonably well co-ordinated; they regulate access based on published Euro style emissions. But the net effect is to complicate road transport operations. Transport managers need to check that their vehicles will meet whatever local LEZs they will encounter. The fact that many LEZs even within the UK seem to apply differing levels of Euro standards and use different enforcement systems and may add vehicle weight restrictions too means another layer of complication.

Still no limits for CO²

The very slow pace toward automotive CO² restrictions seems odd, given the public and political focus on the damaging effects of CO² emissions. Politicians, pundits and others talk about green agendas, carbon footprints and sustainability. Against this background, operators often face a bewildering barrage of claim and counter claim for the benefits of the latest vehicles and related technology.

As usual, this April’s UK Commercial Vehicle Show at Birmingham’s NEC provided a showcase for a huge range of products, systems and services designed to help operators cut costs and carbon footprints. Many of these offer the chance to make a valuable difference, with a huge range of technology and support systems that can help deliver big fuel, cash and CO² savings.

In reality, the simplest and most effective way to cut pollution is to burn less fuel, in this case diesel.

Under ideal conditions, there is a fixed ratio between burning diesel and CO² production because one litre of diesel burns with air to produce 2.65kg of CO², whether it burns in turbocharge cooled truck or bus engine or on a bonfire. That 1:2.65 ratio is also the basis of diesel-based carbon footprint calculations, and so with a known fuel use figure it is easy to do the maths and show the volume of CO² for a job, an increasingly important part of many transport tender submissions. All this reinforces the importance of fuel economy and fuel use data. For sources of data, see, ec.europa.eu,

Don’t forget the driver

It also underlines the importance of the most frequently neglected fuel saving device, the driver. For the last 35 years, truck makers have said and shown that after just a day’s training a receptive driver could cut fuel use by between 10% and 15%. Much of this depended on learning to stick to well thought-out engine speeds. The problem was and remains that drivers are human and forget to do this. As they slip back into old habits, the savings slip too.

The almost explosive growth in telematics, with sophisticated and real time monitoring, means that on-board systems can help a driver keep to the program and get the best out a vehicle. It can also help a fleet manager see how vehicles actually operate, also in real time if necessary. Until, or if, automated and robotically driven vehicles start to take over, it is difficult to see a fleet manager might improve driver control and communication.

Importantly, telematics in its widest sense also offers a growing opportunity to cut fuel use and thus emissions. There are some employee relations opportunities too — not all drivers are happy about the sophisticated “spy in the cab” features that are coming their way.

We all have a role

Legislators too seemed to struggle with the emission reduction implications of telematic driver monitoring. Hopefully, they will get to grips with the opportunities in time to incorporate some of the thinking in the design of Euro VII regulations. In the meantime, fleet managers and their drivers have a valuable opportunity to show the scope of their fuel savings and emission control programs. They can also show that everyone has a role to play in the struggle to reduce emissions, now and in the future.

Footnote on Euro references

The parameters for car, van, truck and bus emission limits are different. Light vehicle limits look at distance, while those for heavy vehicles look at engine power: the two sets of standards are in no way comparable.

To help underline those differences, EU officials decided to use normal numerals for the car regulations and roman numerals for the truck and bus regulations.

This has possibly created more confusion than it cleared, particularly among people who had neither learned Latin at school nor appreciated the seemingly subtle presentational differences. Recently, an increasing number of EU websites now simply use normal numerals.

Car and truck emission standards are completely different: each measures different data.

  • Car and van standards look at the amount of pollution over distance, eg 0.060 grammes of nitrogen oxides a kilometre (or 0.060gNOx/km).

  • Truck and bus standards look at the amount of pollution for a unit of engine power, eg 0.4 grammes of nitrogen oxides a kilowatt hour (or 0.4gNOx/kWh).

Comparisons between the two simply don’t compute; they are in the apples and pears league.