Ecu, they tune the car by what it can handle, every car gets his own tuning on a dyno. they have allot of experience in tuning. They wont add more bhp if the car cant handle it. My car had stock 106 bhp tuned 155. But there were other mk7 1.6tdi they had 150, 145, 154,....
i love it, car handle's much better, i have power when i need it on the highway. everybody has their own opinion. some people say you better bought a 2.0 i nstead of the 1.6 they cant handle the power. i call that BS. if you treat your car right, doing its service on time, checking enigne oil, using good diesel, getting the car engine on temprature, not blasting it full pedal all the time. you cant do anythinng wrong imo.
well thats my opnion.
i like it.
sorry for my bad english xD