Quantum Tuning - anyone heard of it?

cepheus

Every car will have to meet emission limits during a driving cycle which includes motorway driving up to 120 kph (75mph), of course this isn't perfect, it never is.

Any car will pass the MOT emissions test unless something has failed, the in-service limits are set so liberally and allow for substantial wear and tear throughout the cars lifetime. NOx and particulate aren't even measured in an MOT test, that's how these outfits get away with fiddling with the ECU.

What these cars might not pass is the type approval test. Air quality regulations assume most vehicles will still pass those tests with a little extra added on for wear and tear. Without actually measuring NOx, HC, and CO on a loaded rolling road and full EC cycle under the new settings, you can't be sure it would still pass or even be nearer to type approval conditions.

It's not even clear if your fuel consumption would better or worse under the new settings. Manufacturers need to measure fuel consumption and CO2 across the same cycle and are eager to drive this down to beat the competition and qualify for lower tax bands.

This is for commercial vehicles but it gives you an idea

http://www.automotiveworld.com/news/commercial-vehicles/78792-the-dubious-trade-of-rechipping