Considering an ECU remap for your BMW 8 Series 840d 340hp? A Stage 1 remap can take this G15 - 2018 -> diesel mhev engine from 340 BHP to 380 BHP and from 700 Nm to 750 Nm of torque (naturally aspirated). This engine scores 3.5/10 for remap suitability. Get a free personalised quote from a trusted remap professional and find out exactly what your BMW 8 Series can achieve.
Comparisons are calculated from our own recorded Stage 1 figures.
The BMW 8 serie 840d 340hp is a 3.0L naturally aspirated diesel mhev engine producing 340 BHP and 700 Nm from the factory. With a typical Stage 1 remap, output increases to approximately 380 BHP and 750 Nm — a gain of around 40 BHP (12%) and 50 Nm (7%).
This engine has limited remap suitability, with gains weighted towards peak power — the improvement is most noticeable at higher RPM. The tuning headroom is classified as limited, based on the percentage gain available from the factory output.
From a technical perspective, the transmission is many variants use zf 8-speed automatic (where fitted); manuals also exist. at this torque level, transmission and driveline servicing history becomes especially important..
Considerations: Naturally aspirated engine: gains are usually limited; results vary widely.. High tuned torque: check transmission torque capacity and service history.
All figures shown are typical estimates based on aggregated Stage 1 data for this engine variant. Actual results depend on vehicle condition, mileage, and the chosen tuning method. We recommend discussing your specific vehicle with a qualified remap professional.
| Engine | BHP | Gain | Torque | Gain | Score |
|---|---|---|---|---|---|
| 840d 320hp | 320 → 400 | +80 | 680 → 800 | +120 | Good (7.5/10) |
| 840i 340hp | 340 → 400 | +60 | 500 → 580 | +80 | Moderate (5/10) |
| M850i 530hp | 530 → 660 | +130 | 750 → 880 | +130 | Moderate (5.5/10) |
Get a personalised remap quote for your BMW 8 Series. We'll connect you with a trusted professional in your area.
All figures shown are typical estimates based on aggregated Stage 1 data for this engine variant. Actual results depend on vehicle condition, mileage, and the chosen tuning method.
We recommend discussing your specific vehicle with a qualified remap professional before proceeding.
