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BMW N55 ECU Tune
Purchase BMW N55 ECU Tune
  • SKU: 05-455-00075-1

    BMW N55 ECU Tune

  • Advertised gains are estimates of HP and Torque “at the engine” calculated from gains as measured on a Dynojet Dynamometer in ideal conditions and typically show the largest possible change.  Actual gains are dependent on the following: Learn More about Crank HP Vs Wheel HP

    Model – Manufacturers use the same engine in multiple model vehicles and often times they are in a different state of tune, for example: 2008 C63 and a 2008 CLK Black Series.  Both have the same engine, but the C63 has 451hp while the CLK63 has 500hp.  Naturally the C63 will show more gains as it starts at a lower level.

    Model Year – Similar to above, as time progresses, Manufacturers tend to slightly increase power output via software from one year to the next or offer “Performance Packages” with increased power.  The engines remain largely unaltered and as a result, final tuned output remains the same, while the gains are lower as the starting point is now higher.

    Fuel – Fuel quality is HIGHLY important with performance vehicles.  Low quality and/or low octane fuel will greatly impact engine output and potentially even engine health.  Top tier brand premium fuels should always be used to achieve the best results possible.

    Drivetrain – All wheel drive has higher drivetrain losses than rear wheel drive.  This results in lower numbers when testing on a chassis dyno.  Wheel/tire size and weight will also impact chassis dyno results

    Weather/Conditions – Temperature, humidity, altitude, and air density all impact engine performance.  Heat, high humidity, and thin air will all work towards reducing engine output

    Engine Health – Higher miles tends to result in increased build up and lower compression which can and will impact engine output.  Properly maintained engines will have better performance than abused or neglected engines.

    Supporting modifications – The highest power levels require supporting modifications.  Depending on the engine, this could mean forged internals, built transmission, upgraded fuel system, 110+ octane race fuel, etc.

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  • Prop 65 warning

    This product can expose you to chemicals including carbon black, silica - crystalline, formaldehyde, and lead which are known to the State of California to cause cancer, and lead, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to

Weistec Horsepower 424
Weistec Torque 407
Manufacturer Weistec
Street legal in all the US States No
Engine Family N55
Stock Horsepower 349
See more
year make model trim engine
2018 BMW X4 M40i 8AT (F26) Turbo 3L I6 (N55)
2015 BMW X1 xDrive35i 6AT (E84) Turbo 3L I6 (N55)
2014 BMW X1 xDrive35i 6AT (E84) Turbo 3L I6 (N55)
2013 BMW X1 xDrive35i 6AT (E84) Turbo 3L I6 (N55)
2012 BMW X1 xDrive35i 6AT (E84) Turbo 3L I6 (N55)
2019 BMW X6 xDrive35i 8AT (F16) Turbo 3L I6 (N55)
See more

Product Description

All 2020 models require bench flashing at this time.

ECU Tuning Process: How do I get my ECU tuned?

The N55 vehicles are built very stout from the factory and respond beautifully to modifications.  While they have great performance right off the show room floor, it is just too hard to leave them untouched. 

The Weistec N55 Tune provides solid gains throughout the entire powerband, with gains of +60WHP* and close to 60WTQ* torque!  This is on an otherwise 100% stock vehicle, including the air filters.

In addition to the performance gains, there are a couple options available for race vehicles.  First is the "Burble".  This is best compared to that of the M4 GTS "burble" which comes from the factory with this in a mild form.  You can choose "Off" "Mild" or "Aggressive" for the "Burble".  Many seem to prefer "mild", but we gladly will let you choose based on your preference.

Please check with our compatibility list below to see if your vehicle can benefit from Weistec's ECU Calibration!


Cypher Handheld | Powered by Weistec

The Cypher is an optional upgrade when purchasing a Weistec tune for your Fxx series BMW. Simply navigate our website to the tune you wish to purchase. On the tune's product page there will be a drop-down menu giving the option to add Cypher to your tune order. From there, the order is processed, and a Cypher tool will be shipped to you

  • No need to send in your ECU / DME computer
  • Swap tunes file or return the stock within minutes.

Weistec N55 ECU Power 

What does all this mean to you?  More power, sharper throttle response, and consistent performance with out sacrificing refinement. 

Key Features:

  • Improved Throttle Response

  • Optimized Fuel, Spark, and Boost

  • 60 Wheel Horse Gains*

  • 60 Wheel Torque Gains*

  • "Burble" Options (for Race Vehicles only)

  • Cold Start (for Race Vehicles only)

  • Disabled Speed Limiter

*Power gains vary based on model, modifications, fuel, and running conditions.

Tuning Process: Cypher Handheld Tuner