[A_Beer_Clinked]

I could imagine a scenario where this started out as something less evil. Seems to me that cars will perform differently in a lab than on the road; off the top of my head: - Stationary cars have different air-intake characteristics - The temperature of the fuel and air is likely different - The humidity of the air might be different - The fuel in the tank is stationary not sloshing around

There may well be valid reasons for the software to vary engine parameters test mode; maybe to compensate for the above.

Then sometime later someone said "This NOx Reduction module is killing fuel efficiency on the open road, how about we turn it off"

The net result is the same but motives and intentions of the individuals are important.