What are the differences between N54 and N55?

[McGabriella]

n54 and n55 differences are as follows: 1. N54 Engine: The BMW mass-produced turbocharged engine was developed from the N52 series, also featuring an inline 6-cylinder design. At that time, BMW did not yet have the twin-scroll turbo technology patent, and to provide sufficient intake and exhaust volume for the 3.0-liter inline 6-cylinder engine, the turbo had to be large enough. This would inevitably cause significant turbo lag. To reduce turbo lag, the BMW N54 ingeniously adopted a twin-turbo design, which directly solved the turbo lag issue and improved torque output across the rev range. 2. Updated Version: The N55 is an updated version of the N54. The N55 uses a single turbo, while the N54 uses twin turbos. The N55 was introduced to address the high-pressure fuel pump issues prevalent in N54 models, though at least the 335-IS version still uses the N54.