Jos Dings, director of Brussels-based Transport & Environment, told Automotive News (sub. req.) that official CO2 emissions results posted by automakers are "less and less a reflection of what we are seeing on the road." Dings says that the amount of CO2 emitted under controlled test conditions can be up to 50 percent lower than in real-world driving, telling AN that, "We don't want cuts on paper. We want them in reality."
While its hard to dispute that stop-start technology, downsized engines and low-rolling resistance tires have slashed CO2 emissions, test results often times don't align with reality, says Gareth Hession, vice president of research at JATO Dynamics.
Sigrid de Vries, spokeswoman for ACEA, told AN that Europe's current testing methods date back to the 1970s and do not account for changes in driving conditions and technologies that did not exist back then. De Vries adds that a global emissions test is the ultimate goal and admits that without worldwide standards, car buyers should always be leery of published CO2 figures.
[Source: Automotive News – sub. req.]