VW Diesels

JCL · #32 09-29-2015, 03:08 PM

Interesting read from a slightly different perspective, about Euro carmakers and the differences between published emissions results and those achieved in practice.

The study linked below shows what the spread is for various popular vehicles, including some BMWs, and includes a discussion on some of the optimization methods used. Things like pushing the brake pads back into the calipers and taping over the door seams before a test. Changing tires for low rolling resistance tires, and overinflating. The background is that in Europe that is no central EPA group that does the test, rather manufacturers hire their own testing agencies and report the numbers. Those numbers aren't just for consumers who want to know what their fuel cost will be, they are the basis of tax rates and green vehicle incentives, and so on. That means that governments are pursuing automakers regarding potentially inflated claims, as tax fraud.

Bosch, who supplied the cheat software to VW, were referenced by a source who claimed the same software was supplied to BMW. BMW denied using it on vehicles for sale, and there is no evidence of a similar cheat. But there is a wide gap between reported and real world numbers, 48% in the case of the 5 series.

More of the iceberg.

Quote:

The system of testing cars to measure fuel economy and CO2 emissions is utterly discredited. This report analyses the gap between test results and real-world performance and finds that it has become a chasm, increasing from 8% in 2001 to 31% in 2012 and 40% in 2014. Without action this gap will grow to nearly 50% by 2020.

Mercedes cars have the biggest average gap between test and real-world performance, with real-world fuel consumption exceeding test results by nearly half. None of the improvement in emissions measured in tests of Opel/Vauxhall cars since 2008 has delivered improvement on the road, and their real-world fuel economy is actually getting worse. Just a fifth of the apparent improvement in emissions from the launch of the Mark 7 VW Golf (Europe’s best-selling car) have been achieved on the road.

Full report:

http://www.transportenvironment.org/...2015_FINAL.pdf