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BMW 3 Series G20/G21 B48 Models

This page covers the BMW 318i, 320i and 330i from the G20/G21 3 Series generation, built approximately 2019–present. Every variant on this page uses the B48, a 2.0L turbocharged inline-four petrol engine. Covered body styles are Sedan and Touring. Depending on the variant, it was offered with rear-wheel drive or xDrive all-wheel drive, paired with an automatic gearbox or a manual gearbox. Engine management is by a BMW DME; identify the exact ECU hardware and software from the vehicle before ordering a file.

Model & Generation Context

Engine family

B48

Exact revision is production-date and vehicle-specific

Displacement

2.0L

Production

c. 2019–present

Approximate; confirm the build date from the vehicle

Fuel Type

Petrol

Supported Model Variants

BMW 318i

Engine: B48

Production: c. 2020–present

Chassis: G20, G21 · Sedan, Touring

Drivetrain: RWD

BMW 320i

Engine: B48

Production: c. 2019–present

Chassis: G20, G21 · Sedan, Touring

Drivetrain: RWD, xDrive

BMW 330i

Engine: B48

Production: c. 2019–present

Chassis: G20, G21 · Sedan, Touring

Drivetrain: RWD, xDrive

Engine Platform

BMW B48 Engine Hub

Platform overview, tuning paths, reliability notes and diagnostics

All BMW B48 Models

Every model in the directory using the B48 engine

ECU & Transmission Context

BMW DME — identify from vehicle

Read the ECU hardware and software numbers from the vehicle before ordering a file.

Automatic gearbox

Gearbox specification is vehicle-specific; confirm it from the vehicle order data.

Manual gearbox

Gearbox specification is vehicle-specific; confirm it from the vehicle order data.

Identification & Pre-Tuning Checks

  • Confirm the engine code on the vehicle matches the B48 before ordering a file.
  • The exact engine revision is production-date and vehicle-specific; it is not inferred from the model name.
  • Identify the BMW DME and its exact hardware and software version from the vehicle; it is not inferred from the model name.
  • Scan for stored fault codes and resolve existing issues before any calibration work.
  • Gearbox type varies on this model; note whether the car is manual or automatic when submitting a file.

Available Service Paths

Stage 1 Calibration File

A vehicle-specific calibration for a healthy engine on standard hardware. Includes ECU file review, fuel and hardware assessment.

Request a Stage 1 File

Stage 2 Calibration Review

Review your supporting hardware, thermal setup and fuel configuration before requesting an upgraded calibration file.

Review My Stage 2 Setup

Custom Calibration and Datalog Review

Submit datalogs and vehicle configuration for a fully custom calibration review tailored to your specific setup.

Request a Custom Calibration

ECU Read and Support Check

Verify your ECU hardware and software version is supported before starting a calibration project.

Check ECU Support

TCU Calibration Assessment

Assess transmission control unit compatibility and calibration options for your vehicle and gearbox configuration.

Request a TCU File

Pops and Bangs Request Review

Submit a request for review. Availability depends on vehicle setup, hardware configuration and local road-use requirements.

Availability depends on vehicle setup, hardware and local road-use requirements. Not available for all configurations.

Submit for Review

Related Resources

BMW Pre-Tuning ChecklistStage 1 vs Stage 2 ExplainedWhen to Diagnose Before TuningBMW Petrol Tuning GuideBMW 3 Series G20/G21 Dyno Project

BMW B48 File Service

Order a file for your BMW 3 Series

Prepare the original ECU file, vehicle details, fuel and hardware setup before opening a file request.

Open File Service Portal

Original ECU File

Read via OBD, Bench or Boot

Vehicle Details

Model, year and specification

Fuel Information

Fuel type and octane rating

ECU Identification

Hardware and software version