B48 Complete Build Guide

Introduction: B48s come in a few configurations. Identifying which one you have will help you choose the correct mod path. Bimmercat helps you determine what engine you have according to your vin. All "B48s" in the United States are SULEV and therefore have a different designation known as the B46. Both engines are practically identical but it is important to note when buying a downpipe they are different.  B48A/B46A: 11.0:1 Compression 181bhp/200ft-lbs Stock (20i/30e Models) B48B/B46B: 10.2:1 Compression 248bhp/295ft-lbs Stock (30i Models 2017-2018) B48TU/B46TU: 10.2:1 Compression 255bhp/295ft-lbs Stock (30i Models 2019+) B48E (TU Variant): 9.5:1 Compression 301bhp/332ft-lbs Stock (35i Models 2019+) Warning to...