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Want to compare Autogas emissions against those of other fuels?

A German-government database shows that Autogas, at the tailpipe, emits 11% less carbon than gasoline and far less NOx than diesel.

And it promises to show a lot more. By Eric Johnson, Managing Director of Atlantic Consulting and Editor-in-Chief of Environmental Impact Assessment Review.

If you’ve been wondering whether man-made global warming is real, here’s the official answer. In its latest report, published in September 2013, the Intergovernmental Panel on Climate Change opined: “It is extremely likely [95 percent confidence] more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.”

So, in a word, yes. Carbon dioxide (CO2) really is heating the earth. And ‘local’ air pollutants – carbon monoxide, hydrocarbons, nitrogen oxides (NOx) and soot – bring no joy either. They cause sickness and death in plants, animals and humans. With world population trending toward 9 billion and most of those to be located in cities, it is no wonder that governments continue to push down the lid on automotive emissions. September 2014, for instance, will see the debut of Euro VI, the sixth revision of European Union (EU) tailpipe standards, which will ratchet down limits another notch.

As emission limits go ever lower, a key question arises for anybody in the Autogas supply chain: how does Autogas compare with other fuels? Comparisons from the past show Autogas to be better than gasoline or diesel on a number of factors – but are these still valid?

The good news is that on CO2 and NOx, they do appear to be valid. Indeed, more valid than ever before, because the depth of available data is now vastly greater than ever before. A new database, compiled by the German government from tests of more than 5 000 cars actually on the market, offers a massive resource for emission comparisons. If you are in the Autogas supply chain, you ought to know about it.

Down and dirty

Databases of automotive emissions have come a long way in the past 15 years. In the late 1990s, they consisted mainly of what I call ‘one car’ models. Data published by authorities such as the EU’s Environmental Directorate, the US Department of Energy or the California Air Resources Board would compare a single car fuelled by petrol against one fuelled by diesel, sometimes adding in one powered by Autogas and/or compressed natural gas (CNG), and sometimes adding in electricity and hydrogen as well.

This one car was a representation of reality, based on a combination of theoretical calculations as well as actual testing. It was a single data-point, meant to represent the thousands of models operating in the real world.

In 2004, comparisons took a step forward with the publication of the European Emissions Test Programme (EETP), which was sponsored by, among others, the AEGPL. Costing a reported €350 000 (to buy and test some 20 vehicles at the UK’s Millbrook proving grounds), EETP published individual emissions profiles of real, commercially available cars.

More recently, data availability has expanded massively beyond that. As part of the registration process to sell new cars in Europe, EU governments require manufacturers to submit a dossier listing all sorts of details for each model, including the results of a dynamometer test for per-kilometre emissions of CO2, local air pollutants (noted above) and even noise.

The CO2 data can be accessed in each EU member state via the Internet; Google it and see for yourself. This is part of the Energy Using Products (EuP) Directive, which lists fuel usage and carbon emissions of not just cars, but a host of home appliances such as washing machines, refrigerators and cookers. The local pollutants are harder, but not impossible, to access. Germany‘s Kraftfahrt Bundesamt (KBA, which means the Automotive Transport Agency) has compiled them into a massive database of some 355 000 records that dates back about a decade and covers testing under Euro III, IV and V protocols. Through lengthy negotiation and a payment, Atlantic Consulting has secured a copy of this KBA database – a goldmine of potential comparison.

The news so far

Its first finding was presented in early October as a side event to the London WLPGA Summit. As The Times newspaper reported (www.drivelpg.co.uk/news/the-times-ministers-blamed-for-silent-killer-air-pollution-epidemic/), a comparison of 1 251 bi-fuelled vehicles showed that Autogas, on average, emits 11% less CO2 per kilometre at the tailpipe than gasoline. Although this advantage has been suggested in previous studies (summarised in an Atlantic Consulting report for the AEGPL), it was reflected in only some of the ‘one car’ models. Some governments have admitted, in private, that they do not believe Autogas’ carbon superiority; this might explain their weakness in granting it concessions.

Thankfully, the KBA data are robust enough to settle any shadows of doubt. These are real cars, real tests, conducted by an independent, respected authority, and the sample is large enough to rule out any sort of statistical anomaly. This is truly an ‘apples-to-apples’ or ‘like-to-like’ comparison. The cars are completely identical: they are the same car, running on each fuel. Autogas really is lower carbon than gasoline, case closed.

The KBA data also are telling a story about NOx. Autogas emits this pollutant at levels an order-of-magnitude lower than do similar diesel automobiles. At least this is the case for a major European brand, for which the data have been analysed so far. The comparison is not as simple as that for CO2, and needs to be extended to other models and motors.

And then come the other comparisons: CO, hydrocarbons and soot. Not to mention Autogas versus CNG, hydrogen, hybrids and the rest. We have the data; all we need now is the money to fund the analysis. Rest assured, it will cost a lot less than €350 000 and the results will be more robust than ever before.

If you want to be part of this effort or want to see results, drop us an email at auto@ecosite.co.uk.