Stage 2 CLS500 – M278 BiTurbo (CLS550 in USA) – Tuning Results

All gear heads have the same way of thinking….. “There is never enough power!”.  That being said, this is why tuners offer packages like “Stage1” or “Stage2” for example.

Mercedes Benz power-train “M278” is a 4.7 liter twin-turbo (called “bi-turbo” by Mercedes Benz) monster after tuning. (The M278 power-train is named “550” in the USA and “500” in other parts of the world.) After installing the OE Tuning “Stage1” ECU Tune the car tested picked up +110-130wTq & 100-110wHp to the wheels on the dyno above factory stock specs (dynograph displayed below) running premium pump fuel. When compared during a side-by-side comparison on the street the OE Tuning tuned CLS500 has performance slightly better than a CLS63 biturbo and equal to that of a CLS63 bitturbo with Performance Package.

Baseline vs. ECU Tune

Once “off-road” down-pipes and exhaust are installed, the M278 CLS500 was ready for OE Tuning “Stage2” tuning to suit. The results speak for them  self……. +120-130wHp & +175-185wTq gained on the low-end and mid-range and +105-110wHp on the top-end to the wheels on the dyno running premium pump fuel (dynograph displayed below). So……. You don’t need an AMG to have AMG performance.

Baseline (STOCK) vs. Stage2 ECU Tune

We have Stage1 & Stage2 tuning packages to suit all Mercedes Benz Biturbo 500 & 550 with M278 powerplant. The M278 can be found in CL500 & CL550, E500 & E550, GL500 & GL550, S500 & S550 as well as SL500 & SL550 models. Please call to purcahse down-pipes.

For a trained sales representative, please call +1-818-574-5075 or email


2 thoughts on “Stage 2 CLS500 – M278 BiTurbo (CLS550 in USA) – Tuning Results

  1. Hello
    I have a 2014 GL550 but Im a little confused on the numbers that you show on the pictures from the dyno as they seem a little low from what what it should be.
    Also if I want to do stage 2 only do I need to upgrade any other parts or not and also how much does it cost?

  2. Dynos always read lower when comparing to crank/factory output due to drivetrain and parasitic loss. Also dynos can read low or high when comparing dyno brands.
    More details have been replied via email.

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