BMW M340i G20 / 340i F30 B58 Tuning — Auckland

Professional ECU tuning for the BMW M340i G20 and 340i F30 powered by the B58 3.0L turbo inline-6. MHD OTS flashing and custom dyno calibrations on our in-house Mainline dynamometer. Two generations of BMW's best sports sedan — both incredibly tuneable.

Book Custom Tune Call 0800 276 968

Dyno ProvenReal Results

In-HouseMainline Hub Dyno

SAE J1349Corrected Figures

6,000+Parts In Stock

BMW M340i G20 / 340i F30 Models We Tune

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

M340i G20 Sedan (374hp, Gen2)

M340i G21 Touring (374hp, Gen2)

340i F30 Sedan (326hp, Gen1)

340i F31 Touring (326hp, Gen1)

340i F34 GT (326hp, Gen1)

BMW M340i G20 / 340i F30 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 Power326 hp (340i F30 Gen1) — 374 hp (M340i G20 Gen2)

Stage 1 (Software Only)400–430 hp / 575–580 nm

Stage 2 (ECU + Bolt-Ons)440–460 hp / 620–650 nm

Maximum Potential550–700+ hp (upgraded turbo)

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

Why the BMW M340i G20 / 340i F30?

The M340i G20 is widely considered the best all-round sports sedan BMW currently makes
The 340i F30 was the car that proved the B58 was a worthy N55 successor
Both offer M3-rivalling performance with a Stage 1 tune at a fraction of M3 ownership costs

Look Up Your Tuning Potential

Select your vehicle to see expected power gains

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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 (340i F30))$589

xHP Trans Custom (8-Speed F Chassis (340i F30))$1,589

xHP Trans OTS (8-Speed G Chassis (M340i G20))$769

xHP Trans Custom (8-Speed G Chassis (M340i G20))$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

G20 M340i models with a production date of June 2020 or later require a FEMTO unlock before MHD flashing. F30 340i models are not affected. Additionally, if a pre-June 2020 G20 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.

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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.

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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.

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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.

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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?

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In-House Mainline Hub Dyno

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

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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.

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Full Workshop

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

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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 M340i G20 / 340i F30 Tuning FAQs

How much power does a tuned M340i G20 make?

With EuroLab’s MHD custom dyno tune, the M340i G20 (374hp stock) typically makes 420–430hp at Stage 1. Stage 2 pushes to 440–460hp. With an upgraded turbo, the B58 platform reaches 550–700+hp. All figures SAE J1349-corrected on our Mainline CCS3600 hub dynamometer.

How much does it cost to tune an M340i in Auckland?

MHD OTS (self-flash at home) 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 (OTS) is $769 for G-chassis. FEMTO unlock ($2,800) is required for models produced June 2020 or later. If a pre-June 2020 vehicle has had a BMW dealer software update, a bench unlock ($575 incl. GST) is also required.

Do I need a FEMTO unlock for my M340i?

If your M340i G20 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 G20 models that have received a BMW dealer software update will need a bench unlock ($575 incl. GST). We perform both services in-house. The 340i F30 is not affected.

Is the M340i faster than an M3 with a tune?

A Stage 1 M340i produces around 430hp — comparable to the base G80 M3 (473hp stock but conservatively rated). In a straight line the M340i xDrive with a tune can genuinely keep up with a stock M3 for a fraction of the running cost. It’s one of the best value performance sedans on sale.

What transmission tune should I get for my M340i?

The xHP Flashtool transmission tune is essential. It transforms the ZF 8HP with faster shifts, aggressive gear holding, and raised torque limiters. OTS from $769 (G chassis) or custom from $1,769 for a calibration tailored to your tune level.

Can I tune a 340i F30 and an M340i G20 the same way?

Both use the B58 engine, but the M340i G20 uses the Gen2 B58 with port injection added alongside direct injection. The Gen2 handles ethanol blends better. Tuning approach is similar but the calibrations are different. Both are flashed via MHD.

Ready to Tune Your BMW M340i G20 / 340i F30?

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