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Mercedes-Benz C400d W205/S205 FL ECU Remapping

Mercedes-Benz C400d W205/S205 FL3.0 I6 OM656 · 2018–2021

Stage 1 £399

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4.9/5500+ Google ReviewsSee Google Reviews

The Mercedes-Benz C400d W205/S205 FL (2018 to 2021) leaves the factory with 330 PS and 700 Nm from its 3.0 diesel engine. Our Stage 1 estimate takes it to 395 PS and 800 Nm, roughly 20% more power and 14% more torque.

Stage 1 price

£399

Stage 1 ECU remap

Estimated gain

+65 PS · +100 Nm

Power

Stock
330 PS
Stage 1
395 PS

Torque

Stock
700 Nm
Stage 1
800 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
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More Mercedes-Benz tuning

A-Class W177

A180d 1.5 Diesel

C-Class W205

C220d 2.0 Diesel

C-Class W205

C300 2.0 Petrol

C350d W205/S205

C350d 3.0 Diesel

CLS400d C257

CLS400d 3.0 Diesel

E-Class W213

E220d 2.0 Diesel

E350d W213/S213

E350d 3.0 Diesel

E400d W213/S213

E400d 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 C400d W205/S205 FL Quote

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

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Google Customer Reviews

What Mercedes-Benz Owners Say

See what customers say about their experience with STX Tuning.

Google Reviews

4.9

535 Google Reviews

  • Chris Green

    Aug 2026

    Contacted these guys and they came out within 2 days fixed the car and now all is perfect again really happy with the remap done on my car too very polite, efficient service and would highly recommended

    Posted on Google · view on our Google profile

  • Tiinkerj

    Jul 2026

    I wanted to leave a genuine review, I got my car remapped on the 5th June 2026. Making the appointment was very easy, I didn’t have to wait too long for an appointment and had the option for someone to come to my house if needed. The remap was done within an hour or so. My light did come back on a week after the remap was done, but I was able to clear it with no issues and last weekend I took a 4 hour round trip to the beach and the light did not come back on when usually it does after about 1hr into a drive. The point of my long review is I highly recommend this company and I am very happy with the service provided.

    Posted on Google · view on our Google profile

  • Oscar Rapala

    Jun 2026

    First time tuning my car. Didn’t know what to expect but it was amazing. They explained everything to me clearly, how it works etc and before you know it my car was ready. 10/10 polite service. Will be coming back in the future with serious motors, can tell these guys are professionals judging by tons of performance cars outside.

    Posted on Google · view on our Google profile

  • Jamiah Woodroffe

    Apr 2026

    Really five star service I’ve only got my car the day before I messaged on a Sunday just as an inquiry was more than Happy to take time of the day on a Sunday to fit me in last minute just want to think the whole team very professional and I absolutely love my car. I felt an instant power boost and explained everything to me and packages that I can definitely most likely in the future upgrade to will be definitely coming again.

    Posted on Google · view on our Google profile
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