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BMW 640d Convertible: Stage 1 + xHP Stage 3, 385bhp & 772Nm

8 October 2026 · DC Remapping UK

This BMW 640d Convertible F12 came in for our Stage 1 custom dyno tune for the N57 3.0 diesel, with an xHP Stage 3 calibration for the ZF 8-speed.

BMW 640d Convertible rear three-quarter on the dyno
The 640d Convertible on our 4WD linked dyno.

The numbers

It made 300bhp and 622Nm on the baseline run and left making 385bhp and 772Nm:

MeasurementStockDC Stage 1 + xHP ST3
Engine power300.4 hp @ 4,175rpm385.2 hp @ 3,976rpm
Engine torque622 Nm @ 2,334rpm772 Nm @ 2,315rpm
Wheel power256.1 hp353.3 hp
BMW 640d Convertible dyno graph, stock vs DC Stage 1 + xHP ST3
The dyno printout, stock in red, tuned in blue.

Over 700Nm from 2,000 to 3,900rpm

The gain is not just at the peak. Tuned, this 640d holds over 700Nm from around 2,000 to 3,900rpm and carries more than 100Nm extra from 2,050rpm right through to 4,900rpm, with up to 190Nm more in the mid-range. xHP Stage 3 lets the 8-speed handle that torque properly, with quicker, sharper shifts.

BMW 640d Convertible rear view strapped to the rollers
Strapped down for back-to-back runs.

How it was done

Diagnostics and a health check first, then stock runs on our 4WD linked dyno with live data logging. The engine calibration was built from there with repeated runs, the gearbox was flashed with xHP Stage 3, and the final pulls verified the result. No generic files, original software backed up and fully reversible.

BMW 640d Convertible front quarter on the dyno
Health checked and logged before any tuning.

Got a 640d? See our BMW 640d tuning page, check your car’s gains and price, or read about the 640d Gran Coupé we tuned the same week.

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