It is no secret that Volkswagen 'cheated their way' in beating emissions tests by making use of a 'defeat device' that will give off a false emission. But how do Volkswagen vehicles perform during cheat mode while out on the road?

Consumer Reports recently tested on this by comparing a 2015 Jetta TDI with an older 2011 Jetta Sport Wagon TDI. Both cars have the so-called defeat device but in order for 'Cheat Mode' to be activated, they had to start the car in a very different way which involved having the rear wheel sensors disabled, turning the ignition 'On' without starting the car, and pressing the accelerator pedal 5 times (see in video).

This is what they believed activates the TDI's 'cheat mode'.

Over to the car's performance, the newer Jetta TDI was able to go from 0 – 97 km/h in 9.2 seconds, 0.1 second slower than in Normal Mode. The older Jetta however showed a greater loss in acceleration, reaching 97 km/h in 10.5 seconds, 0.6 seconds slower compared to Normal Mode.

It was during fuel economy testing where the numbers really shifted. In Normal Mode, the 2015 Jetta TDI's economy rating stood at 22.5 km/l (53mpg) while the 2011 Jetta Sport Van was rated at 21.3 km/l (50mpg). On Cheat Mode however, the 2015 Jetta only averaged 21.3 km/l (50mpg) while the 2011 Jetta had an average consumption of 19.6 km/l (46mpg).

In the long run, the slight deviation in fuel economy and acceleration figures will not be too apparent. But Consumer Reports still stated that Volkswagen cars emit 40 times more pollutants than what US federal laws allow during Normal Mode.