Studies have shown that the results of lab techniques to measure car emissions can easily be fixed by using techniques such as taping up doors and windows to minimize air resistance, driving on unrealistically smooth roads and testing at improbably high temperatures.

Studies have shown that the results of lab techniques to measure car emissions can easily be fixed  car makers fix the results by using techniques such as taping up doors and windows to minimize air resistance, driving on unrealistically smooth roads and testing at very high temperatures.
