Tuning · BMW X4 M40i (G02)
X4 M40i
B58 Gen 2
The X4 in M40i form with the Gen 2 B58 underneath. Hand-calibrated from Stage 1 to a fully bespoke big-turbo build. Choose your package, send your build to Samuel, and get a tune that fits the way you actually drive.
Engine
B58 Gen 2
Stock
374 bhp · 500 Nm
Stage 3 ceiling
374 bhp
About this tune
The G02 X4 M40i (2018-present) is the coupe-SUV variant of the X3 M40i, same B58 Gen 2 drivetrain, same MG1CS003 ECU, in a lower-roofline body with the same xDrive system. Stock is 374 bhp / 500 Nm. The X4 M40i is the rarer of the two SUV variants in the UK; tuning works identically to the X3 M40i and uses the same map.
BMW X4 M40i tuning
The B58 Gen 2 in the G02 X4 M40i is the same 3.0-litre single-turbo straight-six fitted to the X3 M40i, M340i, M440i and Z4 M40i — same MG1CS003 DME, same hardware ceiling, coupe-SUV body. Stage 1 targets 440 bhp / 680 Nm from OEM hardware: 66 bhp / 180 Nm gained with no mechanical changes. Stage 2 adds downpipe (OPF delete if applicable) and intake for 480 bhp / 700 Nm. The X4's lower roofline and slightly different xDrive rear bias mean the power delivery character differs from the X3 M40i; the calibration accounts for both. Every map hand-calibrated for the specific car — not the model family.
The G02 X4 M40i (2018–2025) is the coupe-SUV variant of the X3 M40i — same B58 Gen 2 drivetrain, same MG1CS003 ECU, lower roofline and slightly more aerodynamic body. xDrive standard, 8-speed ZF automatic. The X4 M40i is the rarer of the two M40i SUV variants in the UK; the tuning path is identical to the X3 M40i. Samuel calibrates the G02 to the same standard. xHP gearbox calibration is available as an add-on and is recommended at Stage 2 and above.
Configurator
Build your X4 M40i tune
Choose your stage — Stage 1, Stage 2 or Stage 3 — add the options that fit your car, and send the full build to Samuel for a custom remote remap. He'll quote, schedule, and personally calibrate within 24 hours of confirmation.
Add a stage or add-on
£0
Engine guide
What the X4 M40i map revision covers: B58 Gen 2 stages explained
The numbers progression on the B58 Gen 2 is straightforward: 440 bhp / 680 Nm at Stage 1, 480 bhp / 700 Nm at Stage 2. In the X4's coupe-SUV body the torque gain is absorbed with a slightly different chassis feel than in the M340i — the lower centre of gravity makes the additional torque more apparent through direction changes. The TU fuel pump is factory-fitted on all B58 Gen 2 cars, so no additional pump upgrade is required for Stage 2. Stage 3 is bespoke around whatever hybrid or big-turbo spec is submitted. Every map is log-reviewed after the first flash before sign-off.
Stage 1
440 bhp · 680 Nm
No hardware required. The MG1CS003 DME is flashed via the OBD port. BMW X4 M40i Stage 1 unlocks 440 bhp and 680 Nm from the OEM hardware (up from 374 / 500 stock). The BMW X4 M40i G02 tuning starting point, the most cost-effective change you can make to BMW's coupe-SUV performance variant.
Every X4 M40i tune Samuel produces is calibrated individually for the specific car, fuel grade and installed hardware, not a base map loaded and left. BMW X4 M40i tuning done correctly accounts for the G02 chassis weight, xDrive calibration and UK fuel quality; the map is reviewed against your data logs after the first flash and revised before sign-off.
Compatibility
This X4 M40i tune runs on Bootmod3, MHD or MG Flasher — all three flash the B58 Gen 2 over OBD. Compare platforms or see full B58 Gen 2 compatibility.
X4 M40i specs & stage targets
BMW X4 M40i tuning at a glance
- Engine
- B58 Gen 2
- Body styles
- G02 SUV Coupe
- Chassis codes
- G02
- Production
- 2018–2025
- Drivetrain
- xDrive
- Gearbox
- 8-speed ZF automatic
- Stock output
- 374 bhp · 500 Nm
- Tuning ceiling
- ~1000 bhp on the right hardware
| Stage | Target |
|---|---|
| Stage 1 | 440 bhp · 680 Nm |
| Stage 2 | 480 bhp · 700 Nm |
| Stage 3, Hybrid Turbo | 550-1000 bhp depending on spec |
| Stage 3, Big Turbo Kit | 550-1000 bhp depending on spec |
FAQ
X4 M40i tuning — frequently asked questions
Stage 1 on the X4 M40i (G02) targets 440 bhp / 680 Nm from the 374 bhp / 500 Nm factory baseline — 66 bhp / 180 Nm gained from the OEM B58 Gen 2 hardware. The MG1CS003 DME is flashed via the OBD port on BM3, MHD or MG Flasher in around 15 minutes.
This page covers the G02 SUV Coupe (2018–2025) — B58 Gen 2 engine, xDrive, ZF 8HP automatic. Every tune Samuel delivers is calibrated for the specific car, its fuel grade and installed hardware. The X3 M40i (G01/G45) is a separate page.
The calibrated X4 M40i map is delivered to your BM3, MHD or MG Flasher account within 24 hours of payment confirmation. You flash it over OBD yourself in around 15 minutes — Samuel personally calibrates every file, no automated delivery.
A factory warranty can be voided if BMW attributes a specific failure to the tune — that is a personal call. Samuel's X4 M40i maps are calibrated to stay within the mechanical limits of the B58 Gen 2 hardware, and the tune is fully reversible to stock before any dealer visit. Many owners run a tuned X4 M40i without issue.
Yes. Once you've driven the X4 M40i on the new map, send your data logs back through your platform (BM3, MHD or MG Flasher), and Samuel reviews them before sign-off. If anything needs adjusting, the file is revised.
Keep exploring
Keep exploring X4 M40i tuning
Other B58 Gen 2 models we tune: M240i, M340i, M440i, Z4 M40i, X3 M40i, Supra 3.0.
Engine guide
B58 Gen 2 tuning
Every B58 Gen 2 BMW we calibrate, with the full Stage 1, 2 and 3 breakdown for the engine.
Learn moreStages
Stage 1 & Stage 2 explained
What separates Stage 1 from Stage 2 on the X4 M40i, the real-world gains and the hardware each one needs.
Learn morePricing
How tuning is priced
How the licence, off-the-shelf maps and custom calibration are priced. We quote your exact spec, never a fixed menu.
Learn moreGuide
What is bootmod3?
New to remote flashing? A plain-English explainer on the platform and how a custom map reaches your car.
Learn more