Hi, i have a 318d saloon with 2.0 116hp m47 engine (2004/6), and i see all these remap sites on web saying that the 318d could be remapped to 144hp, at other forums they say that the car is basically a factory detuned 320d and the 320d can be mapped to 180hp. What is the differences of the 2 (physically same?) engines? How come the same engine cant do 180 hp?