TESTS – The emissions test was performed in three phases: the first is to repeat the Wltp homologation cycle which takes place on the roller bench and is mandatory for the approval of every new car; the second test is the so-called "highway cycle”, Not included in the approval procedure, which is used to detect emissions and consumption of cars at high speeds; third test, only for cars that have passed the previous ones, is theRde (Real driving emissions), performed on the road by installing a special measuring device called Pems (Portable emissions measurement system) on the car. These three tests give a score obtained, for each car, from the average of the scores on fuel consumption and emissions of pollutants. For hybrid cars, the test phases are carried out with the battery charged at 60-70%; for electric cars, a cycle is performed that combines the Wltp and the motorway cycle, conducted until the battery (initially charged to the maximum) is discharged. It is then measured how many km of cycle have been traveled with the total kWh of the battery.
THE REVENGE OF DIESELS – According to the results obtained from these tests, compared to two years ago the comparison between diesel is petrol it is almost overturned in favor of the first, thanks to the fact that, after the scandal of the Dieselgate, the producers have had to reduce the emissions of pollutants of these engines, to enable them to pass the new type approval tests. It can be said that today a diesel engine compliant with current European 6d-Temp standards pollutes less than a gasoline (see table above). Hybrid cars performed better only if used within the city walls, circumstances where the contribution of the electric motor is greater; in extra-urban routes these cars pollute as much as petrol.