Cooking the Books?

[grober]

The EEC have produced a report detailing how various car manufacturers "improve" their emission figures. Full report here. http://ec.europa.eu/clima/policies/transport/vehicles/cars/docs/report_2012_en.pdf
and a good summary here
Questions raised over car makers' emissions tests | Auto Express
Tricks include
Using smaller wheels to optimise rolling resistance and fuel economy.
Testing a car with a fully charged battery.
Using a certain track in Spain to test vehicles because it has optimum conditions for testing coasting data such as a downward slope, ambient conditions and minimal aerodynamic drag and while tests must be carried out in two opposite directions, regulations do not state that this has to be on the same road, consequently both "directions " of the track might be downhill!
Manufacturers were also found to "precondition" their cars before testing, ensuring certain components {if not the engine} are fully warmed up and sealing any gaps between body parts by taping them up to help lower the vehicle's resistance.

So there you go guys- concerned about your fuel consumption - sellotape is the answer!

 

[moonloops]

Amateurs - simply inject outside air under pressure to the exhaust to reduce % emissions

 

[markjay]

The relevance to the consumer is marginal i.e. only when the emissions actually 'jump' down a notch on the taxation scale.

But it is very relevant to manufacturers trying to reduce their vehicles' emmision across the range to meet European targets (without having to sell cars such as the Signet).

 

[Derek Mc]

Not just emissions, it was proven in the US that certain makers "enhance" the economy figures too