A Brussels-based transport pressure group has accused car manufacturers of cheating the device in a bid to meet emission targets and trick motorists into buying their vehicles.
Transport & Environment (T&E), which can be promoting sustainable policies within the sector, said motorists are having to spend up to a quarter more on petrol than official fractional co2 figures suggest.
New figures claim that a normal new car sold in Europe last year was included with carbon dioxide emissions of 127g/km, which means motorists should be able to drive a distance of 56.5 miles per gallon of petrol.
This would claim that car manufacturers have already exceeded the 130g/km target set for 2015.
Tricks to boost mpg
T&E’s own research found that the true average is far lower, around 45 miles per gallon.
The campaign group said this is achieved by a selection of tricks.
Included in this are taping over gaps within the panel to lessen wind resistance, using ultra-low-friction oils in the gearbox or engine, and angling the wheels to reduce the quantity of tyre which happens to be in contact with the path.
TNO, a Dutch test organisation, learned that these methods are being used while the test vehicle will be driven to ascertain its road load curve.
The data, which is linked to the testing-laboratory’s rolling road, is then entered a computer programme, and the lower-than-normal road load curve brings about better CO2 and mpg figures.
‘Standards being undermined’
In a statement, T&E’s clean vehicles manager Greg Archer said: Fuel efficiency standards…are being undermined by an obsolete test.
The test procedures are a Swiss cheese, filled with loopholes, that car makers exploit to exaggerate improvements in fuel emissions and economy.
The European Commission now wants to introduce a new test within three years’ time which it really is hoped will more closely reflect real-world driving.
However, the proposals are being opposed by car companies, which do not want the new test to be introduced until after 2021 – when they must reduce co2 emissions of most new cars to around 95g/km or risk being fined.
One way to avoid prosecution over CO2 emission would be for manufacturers to sellfractional co2 and can be used to offset any sales more CO2-producing cars.