400d (2.9) - 340ch Tuning
Mercedes S — Detailed power and torque gains by stage.
Gains by stage(2)
Power
340 hp
Torque
700 Nm
diesel
Power
340→400ch
+60 ch
+18%
Torque
700→800Nm
+100 Nm
+14%
OriginalTuned
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Everything about 400d (2.9) - 340ch tuning
Tuning the 400d (2.9) - 340ch found in the Mercedes S is one of the most popular performance upgrades. This engine offers excellent potential for power and torque gains.
On ChiptuneMAP, find verified gain data for each stage, compare tuner prices and find the ideal professional for your project.
Gains summary by stage
On the Mercedes S 400d (2.9) - 340ch, tuning delivers up to +100 hp and +180 Nm depending on the stage. Stock vs tuned figures:
| Stage | Power | Torque | Indicative price |
|---|---|---|---|
| Stage 1 | 340 → 400 hp | 700 → 800 Nm | — |
| Stage 2 | 340 → 440 hp | 700 → 880 Nm | — |
Frequently asked questions
What gains can I expect from tuning the 400d (2.9) - 340ch?
Tuning the 400d (2.9) - 340ch (Mercedes S) delivers significant power and torque gains depending on the chosen stage. Stage 1, with no hardware modifications, offers the best gain-to-reliability ratio.
Is tuning reliable on the 400d (2.9) - 340ch?
Yes, the 400d (2.9) - 340ch is known for its reliability when tuned, especially at Stage 1. It's essential to use a certified tuner with maps tailored to your engine.
How much does Mercedes S tuning cost?
Prices vary by stage and tuner. Check our directory to compare rates from professionals near you.
Should I get a tuning box or an ECU remap?
ECU remapping (modifying the engine control unit map) delivers better results and integration than a plug-in tuning box. It's customized for each engine.
How do I find a tuner for my Mercedes S?
Use the ChiptuneMAP directory to find a certified tuner near you. Compare reviews, prices and specialties.