STX Tuning
WhatsApp STX TuningCall STX Tuning

BMW 840d xDrive G14/G15/G16 ECU Remapping

BMW 840d xDrive G14/G15/G163.0 B57 · 2018–Present

Stage 1 £399

Get my quote →
4.9/5500+ Google ReviewsSee Google Reviews

The BMW 840d xDrive G14/G15/G16 (2018 to Present) leaves the factory with 320 PS and 680 Nm from its 3.0 diesel engine. Our Stage 1 estimate takes it to 380 PS and 760 Nm, roughly 19% more power and 12% more torque.

Stage 1 price

£399

Stage 1 ECU remap

Estimated gain

+60 PS · +80 Nm

Power

Stock
320 PS
Stage 1
380 PS

Torque

Stock
680 Nm
Stage 1
760 Nm

Figures are STX Tuning estimates for a healthy standard car, not a dyno result for your vehicle. Power is shown in PS. These are existing vehicle library estimates, not independently measured results.

Where would you like it done?
01753 439130
WhatsApp STX Tuning

More BMW tuning

1 Series F20/F21

118i 1.6 Petrol

135i E82/E88

135i 3.0 Petrol

1M Coupe E82

1M Coupe 3.0 Petrol

3 Series G20/G21

320d 2.0 Diesel

3 Series F30/F31

320d 2.0 Diesel

3 Series F30/F31

330i 2.0 Petrol

330d E90/E91/E92

330d 3.0 Diesel

330d F30/F31

330d 3.0 Diesel

What we do

More than just ECU remapping.

From Stage 1 and Stage 2 ECU remapping to gearbox tuning and supporting performance upgrades, STX Tuning offers specialist vehicle software and tuning services for compatible petrol and diesel cars and vans.

Explore the available options for your exact vehicle at our Slough workshop, with suitable mobile ECU remapping appointments available across selected surrounding areas.

Not sure which tuning service you need?

Tell us what you drive and what you'd like to achieve. We'll check your vehicle and help you explore the available options.

4.9/5 | 500+ Google Reviews
Get my tuning quoteCall STX Tuning: 01753 439130

Get Your 840d xDrive G14/G15/G16 Quote

Select one or more services and send your enquiry to STX Tuning.

Your vehicle
What do you need?

1 service selected: Stage 1

Where would you prefer the work?
Your details

We save your enquiry first, then WhatsApp opens with your message ready. Press Send in WhatsApp to complete it.

Call STX: 01753 439130
  • 4.9/5 Google rating · 535 reviews
  • Slough workshop
  • Vehicle-specific quotes

No payment needed. We use your details only to handle this enquiry. See our privacy policy.

Google Customer Reviews

What BMW Owners Say

See what customers say about their experience with STX Tuning.

Google Reviews

4.9

535 Google Reviews

  • Tracy

    Jan 2026

    Amazing company, arrived within 2 hours of my call and fixed the problem where another garage had failed. So happy to have the issue resolved, technician was so nice and explained everything, excellent service, highly recommend STX Tuning

    Posted on Google · view on our Google profile

  • Jake Bickmore

    Dec 2025

    STX Tuning were absolutely brilliant. The service was super fast — same day turnaround — and they solved an issue with my car that a main dealer claimed would cost me thousands to fix. It turned out the expensive repair wasn’t even necessary, and STX handled it quickly and professionally. Honest, efficient, and highly recommended!

    Posted on Google · view on our Google profile

  • Matthew Mooney

    Nov 2025

    STX were great! (its within ONYX which confused me when I got there, no biggy, just for anyone else reading it). I happened to be arriving when a guy must have been starting their shift, super helpful and got me to the right person. On the way in they even took the time to show my son the Lambo they had, this type of service is so nice to receive. The young guy we spotted fitting the wheels later on, thank you! In for a Stage 1 remap, all done in 30 minutes, and car drives brilliantly and exceeded expectations. Also at a great price as well. All staff I met were super nice and helpful. Credit to you guys! I will definitely be choose these guys going forward! Highly recommend.

    Posted on Google · view on our Google profile

  • Loizos Kyriacou

    Jun 2025

    Went to remap my GLE 250d and the whole process was smooth from start to finish. Super responsive, and had the job done quickly with zero hassle. The results are brilliant , noticeable power gains straight away and smoother drive overall. Would highly recommend them to anyone looking for a quality remap with excellent customer service!

    Posted on Google · view on our Google profile

  • Debby Cunliffe

    Jun 2025

    Fantastic service. Came to my home on a Sunday to remap my car. Great job done and lifetime warranty plus interest free payment facility over 4 months available. Highly recommend

    Posted on Google · view on our Google profile
Read all Google reviews Ask STX on WhatsApp