[accota]

Okay found it out by google:

Originally Posted by E92Fan
The main engine and mechanical differences between the 320d and 318d are basically as follows:

Larger, uprated turbo charger in 320d
Larger, more efficient intercooler on 320d
ECU mapping
Uprated fuel injectors on 320d
Uprated manual gearbox on 320d, with higher torque capacity and longer ratios
312x24mm front brake discs on 320d (as opposed to 300x24mm on 318d)

fair enough.

As for the e46:
320d 150hp has uprated injectors, turbo, ecu map, higher torque 6speed gearbox, longer differential and standard 300 and 294mm brakes.

As opposed to e46 318d: same size turbo as old 320d 136ps, smaller injectors as like 525d vs 530d, gearbox 5speed max 280Nm, original brakes 286 and 272mm.

The intercooler is the same.

Hope it helps