Cars / Vans · ECU Remapping
Mercedes S 400 CDI (4.0) 250 hp Tuning (2002–)
Factory specification and Stage 1 remap gains for the Mercedes S 400 CDI (4.0) 250 hp (2002–). A Stage 1 calibration adds 40 BHP and 70 Nm — software only, no hardware modifications required.
| Measure | Stock | Stage 1 | Stage 2 |
|---|---|---|---|
Power BHP | 250 | 290 +40 BHP · +16% | 300 +50 BHP · +20% |
Torque Nm | 560 | 630 +70 Nm · +13% | 650 +90 Nm · +16% |
+40 BHP
Stage 1 power gain
+70 Nm
Stage 1 torque gain
Rolling road
Dyno Graph
Power (BHP, solid) and torque (Nm, dashed) across engine speed (RPM). Peak figures match our database exactly.
Hover / touch the graph
Stock: 250 bhp · 560 Nm (peak)
Stage 1: 290 bhp · 630 Nm (peak)
Stage 2: 300 bhp · 650 Nm (peak)
Tuning tool compatibility
This ECU is listed in 4 of 4 manufacturer compatibility databases.
AutoTuner
Supported
ECU: Bosch EDC16CP36
Alientech KESS3
Supported
ECU: Bosch EDC16CP36
Magicmotorsport FLEX
Supported
ECU: Bosch EDC16CP36
Dimsport New Genius / New Trasdata
Supported
ECU: Bosch EDC16CP36
Existing customers upload their ECU file via the Regal Tuning File Portal. New to Regal? Request a quote first.
About this remap
Mercedes S 400 CDI (4.0) 250 hp Stage 1 — what changes
The Mercedes S 400 CDI (4.0) 250 hp (2002–) leaves the factory at 250 BHP and 560 Nm of torque. Manufacturers deliberately detune this engine to separate it from more expensive variants in the range — a Regal Tuning Stage 1 calibration safely recovers that headroom through the ECU alone: no hardware changes, no dyno risk, fully reversible.
Fuelling, boost pressure, ignition and torque limiters are optimised within the safe tolerances of the 400 CDI (4.0) 250 hp powertrain (diesel). The result is 290 BHP and 630 Nm with factory smoothness, cold-start protection and emissions behaviour retained.
Why Regal Tuning
Verified on the dyno, backed by 20+ years
Every calibration is developed and verified by Regal Tuning on an in-house 4WD dynamometer and proven across a worldwide dealer network. Your file is supplied through the Regal Tuning file portal with full technical support, and the original factory file is always kept so the vehicle can be returned to stock at any time.
Figures shown are for this exact engine variant. Gains depend on vehicle health, fuel quality and conditions — we confirm the expected output for your specific vehicle in writing before work begins.
Mercedes S 400 CDI (4.0) 250 hp remap FAQ
How much power does Stage 1 add?
Stage 1 takes the 400 CDI (4.0) 250 hp to 290 BHP and 630 Nm — a gain of 40 BHP and 70 Nm over stock.
Is Stage 1 safe for this engine?
Yes — software-only calibration within the safe mechanical tolerances of the engine, gearbox and drivetrain, developed and verified on our in-house 4WD dyno.
How do I get this remap?
Request a quote with your vehicle details or registration. Existing customers upload their ECU file through the Regal Tuning file portal for a fast turnaround.
20+ years of ECU calibration
Ready to unlock your Mercedes S's real performance?
Tell us your vehicle and registration — we'll confirm support and the exact expected gains for your engine before any work begins.