B48 & B46 Wiki

4-Cylinder Single Turbo (2014-Present)

The BMW B48 is a turbocharged 4-cylinder engine introduced in 2014, succeeding the N20. It features many variants including the B48TU (Gen 2), B48TU2 (Gen 3), B48TU3 (Gen 4), B48E and B48R (M-Lite performance variants), and B46/B46TU (USA SULEV variants). The modular design shares components with the B58 inline-6.

Displacement

1,998cc

Configuration

I4 Turbo

Stock Power

184-315 HP

Compression

9.5:1 - 11:1

Engine Variants

Variant	Compression	Power	Years	Notes
B48	10.2:1 / 11.0:1	184-252 HP	2014-2021
B46	10.2:1 / 11.0:1	184-252 HP	2016-2021	USA SULEV variant of B48
B48TU	10.2:1 / 11.0:1	255-261 HP	2018-Present	Gen 2
B46TU	10.2:1 / 11.0:1	255-261 HP	2018-Present	USA SULEV variant of B48TU
B48TU2	10.2:1 / 11.0:1	255-261 HP	2024-Present	Gen 3
B48TU3	10.2:1 / 11.0:1	255-261 HP	2026-Present	Gen 4
B48E (M-Lite)	9.5:1	302 HP / 450 Nm	2019-2024	Discontinued - replaced by B48R
B48R (M-Lite)	9.5:1	315 HP / 400 Nm	2024-Present	Successor to B48E
B48H	Varies	Hybrid variant	2020-Present	PHEV applications

Models with B48/B46 Engine

F Series (B48 Gen 1)

F20/F21 1 Series

118i, 120i, 125i

F22/F23 2 Series

218i, 220i, 225i, 228i

F30/F31/F34 3 Series

318i, 320i, 330i, 330e

F32/F33/F36 4 Series

418i, 420i, 430i

F45/F46 2 Series AT

218i, 220i, 225i, 225xe

F48 X1

sDrive18i, xDrive20i, xDrive25i

F26 X4

xDrive20i

F39 X2

sDrive18i, xDrive20i, xDrive25e

G Series (B48TU Gen 2)

F40/F44 1/2 Series

118i, 128ti, M135i, 218i, M235i GC

G20/G21 3 Series

318i, 320i, 330i, 330e

G22/G23/G26 4 Series

420i, 430i

G30/G31 5 Series

520i, 530i, 530e

G01 X3

xDrive20i, xDrive30i, xDrive30e

G02 X4

xDrive20i, xDrive30i

G05 X5

xDrive45e (Hybrid)

G29 Z4

sDrive20i, sDrive30i

U Series (B48TU2/TU3)

U06 2 Series AT

218i, 220i, 223i, 230e

U11 X1

sDrive18i, xDrive20i, xDrive23i, xDrive25e, xDrive30e

U12 X2

sDrive18i, xDrive20i, xDrive23i, xDrive25e

U10 X1 M35i

M35i xDrive (B48R)

MINI (F5x/F6x Gen)

F54 Clubman

Cooper, Cooper S, JCW

F55/F56 Hardtop

Cooper, Cooper S, JCW

F57 Convertible

Cooper, Cooper S, JCW

F60 Countryman

Cooper, Cooper S, Cooper SE, JCW

B46/B46TU (SULEV variant) used in USA market vehicles. B48E (M-Lite) used in F40 M135i/F44 M235i. B48R (M-Lite) used in U10 X1 M35i and newer M Performance models.

Articles

Engine Specifications

Detailed technical specs including bore, stroke, compression ratios for all B4x variants.

Performance Upgrade Guide

Stage-by-stage upgrade paths with infographics for all B48 compression variants.

Common Modifications

Recommended upgrades including intakes, intercoolers, charge pipes for both FMIC and W2A cars.

Servicing & Maintenance

Service intervals, fluid specifications, recommended oils, and maintenance best practices.

Turbo Upgrade Info

OEM and aftermarket turbo specs, upgrade options, and max HP ratings for the B48 platform.

Part Cross Compatibility

Parts and specs shared between B48, B48TU, B48E, B58, and S58 engines.

Built Motor Guide

Forged internals guide for high-power builds including pistons, rods, sleeves, and head work.

HPFP & LPFP Flow Data

High and low pressure fuel pump flow rate data and max HP ratings for fueling upgrades.

Injector Flow Data

Injector specifications, flow rates, and max HP ratings for various upgrade options.

Spark Plugs Guide

Spark plug specifications, heat ranges, and recommendations for various power levels.

B48E Retrofit (F-Series)

Complete guide for retrofitting the B48E turbo onto F-series B48 Gen 1 cars.

B48E Retrofit (Mini Cooper)

B48E turbo retrofit guide specifically for Mini Cooper B48 Gen 1 cars.

B48E Retrofit (G-Series)

B48E turbo retrofit guide for G-series B48TU cars.

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