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BMW · Stage 1

BMW 420i Gran Coupe Stage 1

A mobile Stage 1 calibration by MTechTuning, with dealer-level diagnostics before and after tuning.

Published vehicle figures

Stock

184hp

270Nm

Stage 1

260hp

420Nm

Difference

+76hp

+150Nm

Figures published for this vehicle. Results vary with model year, software, fuel and condition, so we confirm what suits your car before quoting.

BMW 420i Gran Coupe Stage 1

This BMW 420i Gran Coupe went from 184hp and 270Nm to 260hp and 420Nm with our Stage 1 calibration, a gain of 76hp and 150Nm.

Add-ons

  • Speed limiter solution
  • Sport dials updated

Advanced dealer-level diagnostics were included before and after.

How much does a 420i gain?

This one gained 76hp and 150Nm. We tune 4 Series across Bristol, North Somerset, Somerset and South Wales.

About this job

The results

Power went from 184hp to 260hp, an increase of 76hp or around 41%.

Torque rose from 270Nm to 420Nm (+150Nm), which is what you feel most in everyday driving: stronger pull from low revs and easier overtaking.

What the work involved

A Stage 1 remap is a software calibration for an otherwise standard car. We refine parameters such as boost, fuelling, ignition timing and torque limits within safe margins, so it pulls harder through the mid-range without any hardware changes.

How we carried it out

  • Diagnostic scan for stored faults before any work
  • Stabilised power supply connected while programming
  • Original software read and saved, so the car can be returned to standard
  • Calibration written, then the car checked again afterwards

Thinking about the same for your BMW?

We come to you from our Weston-super-Mare base, across Bristol, Somerset, Gloucestershire, Wiltshire, South Wales and parts of Devon and Dorset. Results depend on the exact car, so we confirm what suits yours before quoting.

BMW tuning Check your gains
BMW 420i Gran Coupe Stage 1 photographed by MTechTuning
  • Dealer-level diagnostics before and after
  • Fully mobile, at home or work
  • Lifetime software warranty and support
  • 14-day money-back guarantee

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Talk through your vehicle

Find out what your car can do.

Share your registration, mileage and what you would like to improve. We're always online to quote and reply, and we'll confirm what is suitable before booking, then come to you. Fully mobile from our Weston-super-Mare base across Bristol, Somerset, Gloucestershire, Wiltshire, South Wales and parts of Devon and Dorset.

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