Considering an ECU remap for your Mercedes-Benz S 420 CDI 320hp? A Stage 1 remap can take this W221 - 2005 - 2013 diesel engine from 320 BHP to 360 BHP and from 730 Nm to 820 Nm of torque (turbocharged). This engine scores 6/10 for remap suitability. Get a free personalised quote from a trusted remap professional and find out exactly what your Mercedes-Benz S can achieve.
The Mercedes-Benz S 420 CDI 320hp is a 4.0L turbocharged diesel engine producing 320 BHP and 730 Nm from the factory. With a typical Stage 1 remap, output increases to approximately 360 BHP and 820 Nm — a gain of around 40 BHP (12%) and 90 Nm (12%).
This engine has moderate remap suitability, with a balanced spread of gains across both power and torque — providing a noticeable improvement across the rev range. The tuning headroom is classified as moderate, based on the percentage gain available from the factory output.
Considerations: High tuned torque: check transmission torque capacity and service history.. Older diesel: injector, turbo and intake condition can affect results; ensure maintenance is up to date.
Fuel economy note: possible improvement with conservative driving.
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 |
|---|---|---|---|---|---|
| 250 CDI 204hp |
| 204 → 230 |
| +26 |
| 500 → 560 |
| +60 |
| Good (6/10) |
| 320 CDI 211hp | 211 → 260 | +49 | 540 → 600 | +60 | Good (6.5/10) |
| 320 CDI 235hp | 235 → 260 | +25 | 540 → 600 | +60 | Good (6/10) |
| 350 CDI 235hp | 235 → 290 | +55 | 540 → 620 | +80 | Good (6.5/10) |
| 350 CDI BlueTec 258hp | 258 → 300 | +42 | 620 → 700 | +80 | Good (6/10) |
| 400 Hybrid 299hp | 299 → 314 | +15 | 384 → 399 | +15 | Limited (3.5/10) |
| 450 CDI 320hp | 320 → 360 | +40 | 730 → 820 | +90 | Good (6/10) |
| 500 - 388hp | 388 → 408 | +20 | 530 → 570 | +40 | Limited (3.5/10) |
| 500 Turbo 435hp | 435 → 510 | +75 | 700 → 820 | +120 | Good (6.5/10) |
| 600 V12 Turbo 517hp | 517 → 585 | +68 | 830 → 910 | +80 | Good (6/10) |
| 63 AMG 525hp | 525 → 541 | +16 | 630 → 650 | +20 | Limited (3/10) |
| 63 AMG Turbo 544hp | 544 → 590 | +46 | 800 → 900 | +100 | Good (6/10) |
| 65 AMG V12 Turbo 630hp | 630 → 670 | +40 | 1000 → 1100 | +100 | Moderate (5.5/10) |
Get a personalised remap quote for your Mercedes-Benz S. 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.
