Originally Posted by topcat87
320i vs 328i
The 320i and 328i's engine, fuel system, intercooler,downpipe etc etc are exactly the same. Differences would include smaller brakes and exhaust which can be easily changed.
This has been discussed to death in other regions where N20 320 and 328 are available
The only difference is the boost level that the ecu allow the 320i to make which is definitely lower than that of the 328i. This is how BMW differentiates the cars and control the HP output.
So right now once aftermarket tuners circumvent the DME and reflash the 320i engine maps with that of the 328i the 320i is game!!
There's more to it than that, it's also the reason why tuners aren't able to extract the same power/torque as the higher tuned version, be it the Mercedes M271 Evo (184ps vs 204ps) or BMW N20 (184ps vs 218ps vs 245ps) or various turbo diesels (e.g. BMW N47). The only explanation I can think of is that they bin the engines according to wht they can achieve on the factory testbench after assembly.