Petrol Tuning · 2016 – 2019 (F20, F21)
BMW M140i Stage 1 Remap
The B58 is famously under-stressed from the factory. A stage 1 file on a standard M140i is one of the biggest value-for-money gains in modern tuning — 400bhp on stock hardware, stock turbo, stock fuel system.
Typical Stage 1 Gains
Power
+65 bhp
Torque
+100 Nm
Figures are typical results on a healthy, standard vehicle. Every car is calibrated individually, so your exact numbers depend on variant, condition and fuel.
ECU
Bosch MG1CS003
How we read it
Bench read/write on MG1 — no mail-in unlock needed
Price
From £299 · 0% finance over 4 payments
What we do to your BMW M140i
3.0 B58 single-turbo petrol
We read and write the MG1CS003 on the bench in-house, so there's no posting your ECU away and no waiting days for an unlock.
Boost, ignition, cam timing and torque limits are calibrated together, with knock protection left fully active. We do not remove safety limiters to chase a dyno number.
Shift points and torque requests are matched to the ZF 8HP so the car doesn't fight itself under load.
xHP gearbox tune recommended for full stage 1 — sharper, faster shifts
Pops and bangs / overrun crackle available on request
Decat or downpipe files supported (off-road use only)
Lifetime warranty on our software, original file always stored, and no mechanical modifications required. Terms apply.
BMW M140i Remap FAQs
Do you need to remove the ECU?
On the MG1 we bench read and write it, which means the ECU comes out on the day and goes straight back in. No mail-in unlock, no downtime.
Will it hold 400bhp reliably?
On a healthy standard car with good fuel, yes — the B58 bottom end and turbo have plenty of margin at this level. Regular servicing matters more than the map.
Can it be put back to standard?
Yes, we keep your original file and can return the car to stock at any time.