BMW M140i / M240i B58 Tuning — Auckland

Professional ECU tuning for the BMW M140i F20 and M240i F22/G42 powered by the B58 3.0L turbo inline-6. MHD OTS flashing and custom dyno calibrations on our in-house Mainline dynamometer. Compact, lightweight, and extraordinarily tuneable.

Book Custom Tune Call 0800 276 968

Dyno ProvenReal Results

In-HouseMainline Hub Dyno

SAE J1349Corrected Figures

6,000+Parts In Stock

BMW M140i / M240i Models We Tune

All powered by the B58B30 engine — see our B58 Engine Hub page for full engine details, technical specs, and common issues.

M140i F20/F21 (340hp, Gen1)

M240i F22/F23 (340hp, Gen1)

M240i G42 (374hp, Gen2)

BMW M140i / M240i Tuning Power Figures

All figures are approximate, SAE J1349-corrected on our Mainline hub dynamometer. EuroLab develops its own proprietary tune files — calibrated for NZ 98 RON fuel and local conditions.

Power at a Glance

Stock Power340 hp (Gen1) — 374 hp (Gen2 G42)

Stage 1 (Software Only)400 hp / 580 nm

Stage 2 (ECU + Bolt-Ons)420–460 hp / 620 nm

Maximum Potential550+ hp (upgraded turbo)

For full tuning stage breakdowns, hardware requirements, and common engine issues, see our comprehensive B58 Engine Hub page.

Why the BMW M140i / M240i?

The M140i is BMW's last rear-wheel-drive hot hatch — a modern classic
Lighter than 3-Series/4-Series equivalents, so the same tune feels even faster
The G42 M240i's Gen2 B58 with port injection handles ethanol blends even better

Look Up Your Tuning Potential

Select your vehicle to see expected power gains

Make

Model Family

Generation / Year

Engine

Power figures are estimates based on available tuning data. Actual results are validated on our in-house Mainline CCS3600 hub dynamometer and may vary based on fuel quality, ambient conditions, and individual engine health.

Tuning Pricing

Transparent pricing for all tuning options. All prices in NZD.

MHD OTS — DIY Self-Flash

Flash pre-built maps to your ECU at home using the MHD app + WiFi adapter

MHD WiFi Adapter$189

MHD B58 License~$993

MHD Custom Dyno Tune — At EuroLab

Professional custom calibration on our Mainline CCS3600 hub dynamometer. We develop the tune file in-house — MHD is the flashing platform.

Custom Dyno Tune$2,500 incl. GST

Includes baseline dyno run, custom calibration for your specific car, and final validation pulls. Calibrated for NZ 98 RON fuel and local conditions.

xHP Transmission Tune

Transform your automatic transmission with faster shifts, raised torque limiters, and improved gear holding.

xHP Trans OTS (8-Speed F Chassis (M140i F20))$589

xHP Trans Custom (8-Speed F Chassis (M140i F20))$1,589

xHP Trans OTS (8-Speed G Chassis (M240i G42))$769

xHP Trans Custom (8-Speed G Chassis (M240i G42))$1,769

⚠️ ECU Unlocks (If Required)

Some vehicles require an ECU unlock before tuning can proceed.

FEMTO Unlock (June 2020+ production)$2,800

Bench Unlock (dealer software update)$575 incl. GST

G42 M240i models with a production date of June 2020 or later require a FEMTO unlock before MHD flashing. F20 M140i models are not affected. If a pre-June 2020 G42 has received a BMW dealer software update, the ECU may be locked — a bench unlock ($575 incl. GST) is required before tuning.

Stage 3 & Stage 4 — Full Build Programme

Stage 3 (800+whp): Upgraded turbo, ethanol fuel system, supporting modifications, custom calibration.

Stage 4 (1,300+whp): EuroLab’s complete engine and transmission build programme — forged internals, built trans, custom everything.

Call 0800 276 968 or enquire online for a custom quote.

How It Works — Our Tuning Process

Every EuroLab custom tune follows the same rigorous 4-step process.

🔍

1. Consultation & Health Check

We inspect your vehicle, check for fault codes, and discuss your goals. No tuning happens on a car with underlying issues.

📈

2. Baseline Dyno Run

Your car goes on our Mainline CCS3600 hub dynamometer for baseline power and torque measurements — SAE J1349-corrected for honest, repeatable numbers.

🔧

3. Custom Calibration

We develop your tune file in-house, making iterative adjustments on the dyno. Fuel maps, boost targets, ignition timing — all calibrated for your specific car, mods, and NZ 98 RON fuel.

✅

4. Final Validation & Handover

Final power pulls to confirm gains, data review with you, and a road test. You leave with your dyno sheet and a car that performs exactly as promised.

Why Choose EuroLab?

📈

In-House Mainline Hub Dyno

SAE J1349-corrected figures on our Mainline CCS3600 — the most conservative standard. Our numbers are real, repeatable, and honest.

🔧

Custom Calibrations In-House

We develop our own proprietary tune files, calibrated live on the hub dyno for NZ 98 RON fuel. We use MHD as the flashing platform — the tune itself is ours.

🛠

Full Workshop

We don’t just flash ECUs. Diagnostics, repairs, bolt-on installs, turbo swaps — everything under one roof at our East Tamaki workshop.

⭐

149+ Five-Star Reviews

4.8-star Google rating. Our reputation is built on quality work, honest advice, and cars that perform exactly as promised.

BMW M140i / M240i Tuning FAQs

How much power does a tuned M140i make?

With EuroLab’s MHD custom dyno tune, the M140i F20 (340hp stock) typically makes around 400hp at Stage 1. Stage 2 pushes to 420–460hp. With an upgraded turbo, 550+hp is achievable on the B58 platform. All figures SAE J1349-corrected on our Mainline hub dyno.

How much does it cost to tune an M140i or M240i in Auckland?

MHD OTS (self-flash) is ~$993 for the B58 license plus $189 for the WiFi adapter. EuroLab’s MHD custom dyno tune is $2,500 incl. GST. xHP transmission tune from $589 (F chassis) or $769 (G chassis M240i G42). FEMTO unlock ($2,800) required for G42 M240i produced June 2020+. Pre-June 2020 vehicles with a BMW dealer software update require a bench unlock ($575 incl. GST).

Does the M240i G42 need a FEMTO unlock?

If your M240i G42 has a production date of June 2020 or later, yes. The newer DME hardware requires a FEMTO unlock ($2,800) before MHD can flash the ECU. Additionally, pre-June 2020 G42 models that received a BMW dealer software update will need a bench unlock ($575 incl. GST). The M140i F20 is not affected.

Is the M140i the best value B58 BMW?

Many enthusiasts think so. The M140i F20 is BMW’s last rear-wheel-drive hot hatch — lighter than the 3-Series with the same B58 engine. A Stage 1 tune gives it M-car performance at a fraction of the price. It’s a modern classic.

What’s the difference between the M140i and M240i for tuning?

The M140i F20 and M240i F22 both use the Gen1 B58. The M240i G42 uses the Gen2 B58 with added port injection (better ethanol compatibility). Tuning potential is similar, but the Gen2 has a higher ceiling with ethanol. All are flashed via MHD.

Do I need supporting mods for Stage 1?

Stage 1 on the B58 is software-only — no hardware changes required. However, we recommend an xHP transmission tune to complement the ECU tune (the stock transmission calibration can feel sluggish with the extra power). For Stage 2, a downpipe and charge pipe upgrade are typical.

Ready to Tune Your BMW M140i / M240i?

Book your tuning consultation today. Stage 1 daily driver or full-build custom calibration — we’ve got you covered.