N55 vs B58: What Changed and Which Engine Is Better?
Image: BMW B58B30C Complete Engine with just 30K Miles for £7,249.99 at MT Auto Parts For most of the 2010s, a BMW with a 35i badge meant one engine: the N55, a 3.0-litre turbocharged straight-six. From 2015, BMW began replacing it with the B58 engine , and the badges changed to 40i. Both engines are smooth, quick and well liked, but the B58 is a different engine underneath, and the differences matter if you are buying a car or a replacement engine. N55 vs B58 at a Glance N55 B58 Introduced 2009 (F07 535i GT) 2015 (F30 340i) Capacity 2,979 cc 2,998 cc Bore × stroke 84.0 × 89.6 mm 82.0 × 94.6 mm Block Aluminium Aluminium, closed deck Turbo Single twin-scroll Single twin-scroll Intercooler Air-to-air, front-mounted Water-to-air, built into the intake plenum Typical UK cars M135i, M235i, 335i, 435i, 535i, original M2 M140i, M240i, 340i, 440i, 540i, 740i, G-generation 40i and M40i models The BMW N55 Engine The BMW N55 engine replaced the twin-turbo N54 in 2009, first appeari...