Customer BMW X3 M40d (G01, B57) on the DC Remapping 4WD dyno

BMW Tuning / B57 / X3 M40d

BMW G-Series 3.0 Diesel · Case Study

BMW X3 M40d G-Series Stage 1 Remap

Stage 1 Custom Dyno Tune & xHP Stage 3 Gearbox Software

402bhpTuned · from 326

807NmTuned · from 688

£449Stage 1 · inc VAT

Book Your X3 →View Results

4WD Linked Dyno
xHP Gold Dealer
Ground-Up Dyno Builds
14+ Yrs BMW Experience
Customers UK-Wide

The Build

Another G-Series Set Up Properly

This BMW X3 M40d arrived producing 326bhp and 688Nm – impressive from the factory, but the B57 platform has considerably more to give when the calibration is done correctly.

After our Stage 1 custom dyno calibration combined with xHP Stage 3 gearbox tuning, it left delivering a massive 402bhp and 807Nm. That’s a gain of 76bhp and 119Nm from a single day on the dyno.

The transformation is exactly what this platform is capable of when calibrated correctly – massive mid-range torque, sharper throttle response and relentless acceleration, all while maintaining the refinement expected from a modern BMW SUV.

All work was carried out live on our linked 4WD dyno, with full health checks and detailed data logging throughout the process. No generic files. No compromises. Just precision calibration tailored specifically to the vehicle.

Before vs After – Dyno Results

Metric	Stock	Tuned
Engine pwr	326hp	402hp
Engine tq	688Nm	807Nm
Wheel pwr	263hp	337hp

+76BHP Gain

+119Nm Gain

BMW X3 M40d on DC Remapping UK 4WD dyno – front view

BMW X3 M40d engine bay – B57 M Performance

BMW X3 M40d rear on dyno – DC Remapping UK

Dyno Data

The Numbers Don’t Lie

Every run is logged, graphed and printed. Before and after dyno sheets are included with every tune so you can see exactly what your car gained.

BMW X3 M40d Stage 1 Custom Tune + xHP ST3 dyno graph – DC Remapping UK — Stock (red) vs DC Stage 1 Custom & xHP ST3 (blue) · BMW X3 M40d G-Series

Stock BHP: 326
Tuned BHP: 402
Stock Nm: 688
Tuned Nm: 807
Wheel HP Stock: 263
Wheel HP Tuned: 337

Full vehicle diagnostics & health check on arrival
Tune built from zero on our 4WD linked rolling road
Multiple iterative dyno runs – refined until perfect
Detailed live data logging throughout the session
Before & after dyno printout provided

Not a one-off

Four X3 M40ds, all over 400bhp

We’ve had four customer X3 M40ds on our 4WD dyno, each with our Stage 1 map and xHP ST3 gearbox software. Every one finished between 400.6 and 405.7bhp. These are the printed sheets.

BMW X3 M40d

G01 · B57 3.0 diesel · Stage 1 + xHP ST3

Power: ~~324.9~~404.4+79.5
Torque: ~~686~~805+119

Read the build On our results page

BMW X3 M40d

G01 · B57 3.0 diesel · Stage 1 + xHP ST3

Power: ~~326.0~~402.5+76.5
Torque: ~~688~~807+119

On our results page

BMW X3 M40d

G01 · B57 3.0 diesel · Stage 1 + xHP ST3

Power: ~~322.2~~400.6+78.4
Torque: ~~690~~799+109

On our results page

BMW X3 M40d

G01 · B57 3.0 diesel · Stage 1 + xHP ST3

Power: ~~320.0~~405.7+85.7
Torque: ~~674~~799+125

On our results page

“Had my X3 M40D and gearbox remapped at DC, and what a difference it's made, 405bhp and 811Nm end result, very professional and informative”

Jamie Foster · BMW X3 M40d · Google review

xHP Stage 3 Gearbox Tuning

ZF8 Transformed

With xHP Stage 3 installed, the ZF8 gearbox becomes significantly sharper and more intelligent. Shift speeds are quicker, torque management is optimised and gear logic under load is far more decisive – allowing the drivetrain to fully deploy the increased output safely and effectively.

Dramatically faster shift speeds in all modes
Torque management optimised for increased output
Gear logic under load far more decisive
Improved launch control & responsiveness
Gear display across all driving modes
Sport & comfort shift points fully recalibrated

Gold

xHP Gold Dealer
The top tier of the xHP dealer network, with every ZF8 flash done in person at our Warrington workshop.

Why DC Remapping UK

Our Approach

G-Series Specialists

Over 14 years tuning BMWs, and the G-Series 3.0 diesels since they arrived. We know every parameter of these engines and how to extract their full potential reliably.

Custom Engine & Gearbox

Every engine and gearbox calibration is built entirely from scratch on the dyno, matched precisely to each other for optimal driveability and reliability.

Dyno-Proven Results

All results are verified on our 4WD linked rolling road with before and after printouts provided. Repeatable, measurable, proven performance gains.

Safe & Reliable

Full pre-tune health checks, live data logging and iterative dyno refinement ensure every car leaves safely calibrated – not just producing big numbers.

FAQs

BMW X3 M40d Tuning Questions

How much power will a Stage 1 remap add to my BMW X3 M40d?

Our Stage 1 maps are custom-built on our in-house 4WD dyno and tailored to your exact BMW X3 M40d, never a generic off-the-shelf file. You'll see a substantial, fully dyno-proven gain in both power and torque; the headline figures for this platform are shown at the top of this page. Because every map is refined over multiple runs, the results are realistic, repeatable and safe.

Is remapping my BMW X3 M40d safe and reliable?

Yes. We tune strictly within the safe mechanical limits of your BMW X3 M40d's engine and gearbox, monitoring temperatures, pressures and torque loads across multiple dyno pulls. We've spent 14+ years tuning these platforms, so our maps prioritise long-term reliability alongside performance.

Will a remap affect my warranty or insurance?

A remap is an aftermarket modification, so it's the owner's responsibility to declare it to their insurer. Our maps are fully reversible, we keep your original factory file and can return the BMW X3 M40d to completely standard whenever you need, for example before a main-dealer visit.

Is the remap reversible?

Completely. Your original factory software is saved before we start, so your BMW X3 M40d can be returned to stock at any time.

Will tuning improve my BMW X3 M40d's fuel economy?

We tune for performance, not fuel economy, so we don’t promise or guarantee any MPG saving. How much fuel the car uses comes down mostly to how it’s driven, and using the extra performance will use more.

How long does it take, and do you tune on a dyno?

Most Stage 1 tunes are completed within a few hours; allow up to a day for combined ECU and gearbox work. Every BMW X3 M40d is mapped on our in-house 4WD dyno in Warrington, never on the road, so the result is measured and consistent. You're welcome to relax in our customer waiting area while we work.

Check Your Vehicle

See What Your Car Will Make

Pick your make, model and engine for the expected Stage 1 and Stage 2 gains, your price, and book straight from the result.

Make Model Generation Engine

Choose your make to begin.

Ready to transform your X3 M40d?

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