Originally Posted by firechicken99
...is the N54 stronger than the N55?
YES. The N54 has forged everything. Pistons, rods, crankshaft, ect... Everything is stronger and costs BMW more to produce.
The N55 has all cast parts, which are not as strong as forged internals. This is the reason why almost every tuner only delivers (tunes) the N55 for 360 Hp vs 380 ~ 400+ Hp for the N54.