The BMW M240i xDrive G42 produces 374 hp and 500 Nm from the factory. However, the 3.0-liter B58 inline-six has considerably more tuning potential.
In a BMW M240i xDrive G42 tested by MTR Performance, our Stage 2 configuration produced 472 hp and 720 Nm. That is an increase of +98 hp and +220 Nm compared with the factory figures.
In this article, we examine what is possible with a BMW M240i G42, the difference between Stage 1 and Stage 2, and the role of ECU tuning, TCU tuning, and performance hardware.
Short answer: our BMW M240i xDrive G42 Stage 2 delivers 472 hp and 720 Nm on RON98 fuel, measured on our Dynojet 424xLC2. The exact result varies by vehicle, software version, hardware configuration, fuel, and measurement conditions.
BMW M240i G42 Stage 2: our own dyno results
For this BMW M240i xDrive G42, we measured the performance on our Dynojet 424xLC2 4x4 dyno in Rhoon. This means we can rely not only on theoretical power figures, but also show what the car actually delivers on the dyno.
Dyno results BMW M240i xDrive G42
All measurements below were carried out on RON98 fuel.
|
Configuration |
Power |
Torque |
|
OEM |
374 hp |
500 Nm |
|
Measured standard with mods |
409 hp |
548 Nm |
|
MTR Stage 2 |
472 hp |
720 Nm |
From the factory figures to our Stage 2 configuration, this means:
- +98 hp
- +220 Nm
- approximately 26% more power
- approximately 44% more torque
The difference in torque is especially noticeable in everyday driving. While the standard M240i already performs strongly, the higher torque delivery after tuning provides significantly more pulling power across a wide rev range.
Please note: the value of 409 hp / 548 Nm is a measured configuration and not a fully original OEM measurement. The factory figures of 374 hp and 500 Nm are used as a reference.
Also view the full BMW M240i xDrive G42 Stage 2 project for more information about this car.
Which engine does the BMW M240i G42 have?
The BMW M240i xDrive G42 is powered by the B58, a 3.0-liter turbocharged inline-six petrol engine.
The B58 is known as a strong tuning platform and is used in various BMW models. In the M240i, BMW combines the engine with xDrive all-wheel drive and a ZF 8-speed automatic transmission.
For tuning, this combination is interesting for several reasons:
- 3.0-liter inline-six B58 engine
- turbocharged engine with significant tuning potential
- xDrive all-wheel drive for extra traction
- ZF 8-speed automatic transmission
- extensive aftermarket support for the B58
- good combination of everyday usability and performance
The M240i is therefore an interesting base for those who want more power without immediately switching to a full M model.
BMW M240i G42 Stage 1 vs Stage 2
The main difference between Stage 1 and Stage 2 is the combination of software and hardware.
At Stage 1 the ECU software is adjusted while the car continues to run largely with standard hardware. At Stage 2 the software is tailored to a more extensive hardware configuration to enable higher and more consistent performance.
|
Stage 1 |
Stage 2 |
|
|
ECU tuning |
✓ |
✓ |
|
TCU tuning |
✓ |
✓ |
|
Intercooler |
Stock |
Recommended |
|
Intake |
Optional |
Depending on configuration |
|
Downpipe |
Stock |
✓ |
|
Upgraded spark plugs |
Depending on setup |
Depending on calibration |
|
Power |
±450 hp* |
±470 hp |
|
Torque |
±650 Nm* |
±720 Nm |
* Indicative values; final power depends on fuel, hardware, software version, and the specific car.
For Stage 2, we therefore always recommend looking not only at maximum power, but at the complete combination of ECU software, transmission software, hardware, fuel, and temperature management.
Which hardware upgrades are important for BMW M240i G42 tuning?
More power also means more heat and greater loads on various components. That is why hardware can play an important role in a Stage 2 configuration.
Performance intercooler
At higher power levels, the B58 produces more heat. A larger or more efficient intercooler helps keep the intake air temperature under control.
This is particularly important under repeated load. When the intake air temperature becomes too high, the ECU may reduce power to protect the engine.
A performance intercooler can therefore contribute to more consistent performance, especially during intensive use.
View our performance intercoolers.
Performance air intake
A performance intake can improve airflow to the turbo and is part of various B58 performance configurations.
Whether an upgraded intake is actually necessary depends on the selected setup and the desired power target.
View our engine performance parts.
Performance downpipe
A downpipe affects exhaust gas flow on the turbo side and, in certain performance configurations, can contribute to lower exhaust back pressure.
The relevance and suitability of a downpipe depend on the selected software and hardware. Applicable laws and regulations for use on public roads must also be taken into account.
View our performance downpipes.
Upgraded spark plugs
A tuned engine may place different demands on the ignition under higher loads. That is why upgraded spark plugs can be part of a performance setup.
Which spark plugs are suitable depends on the specific software and hardware configuration.
View our performance spark plugs.
ECU tuning for the BMW M240i G42
The ECU determines, among other things, how the engine manages boost pressure, fuel, ignition, and torque. By adjusting the software, the B58 can be better tailored to the desired performance configuration.
That is why a good ECU tune is not only about one maximum horsepower figure. The way power and torque are delivered is also important.
At MTR Performance, tuning is combined with dyno measurements. This allows us to tailor the software to the specific car and verify the results.
For a M240i G42, this means a combination of:
B58 + ECU tuning + suitable hardware + RON98 + dyno validation.
TCU tuning: why is it important for a tuned M240i?
The BMW M240i G42 uses a ZF 8-speed automatic transmission. Once engine torque is increased significantly, the transmission must also be calibrated to the engine’s new characteristics.
TCU tuning focuses on, among other things:
- adjusted torque limits
- shift points
- shift speed
- cooperation between the ECU and transmission
- launch control
- the behavior of the transmission under higher load
With our Stage -configuration, TCU tuning is therefore an integral part of the overall setup.
The goal is not simply to make the gearbox shift more aggressively, but to to make the engine and transmission function as one integrated system.
View our ECU & TCU software.
How reliable is a BMW M240i G42 with Stage 2?
Higher power always puts greater strain on the engine, transmission, and thermal systems. That is why it is important not only to look at the dyno result, but also at how the car is maintained and used.
Temperature management
At higher power levels, heat management becomes increasingly important. An efficient intercooler and good thermal control help keep performance stable during repeated load.
Fuel quality
For our Stage 2 setups, we recommend RON98. The exact fuel requirements depend on the software calibration used.
Maintenance
Regular maintenance becomes even more important with a tuned car. This includes engine oil, spark plugs, filters, and transmission maintenance.
View our maintenance & repair service.
Tuning for the specific car
No two cars respond exactly the same. Software version, hardware, fuel, mileage, and test conditions can all affect the result.
That is why we validate our tuning on our 4x4 dyno in Rhoon.
Read more about our live dyno testing.
BMW M240i G42 vs BMW M3: which has more tuning potential?
The BMW M240i G42 and BMW M3 are both powerful BMW models, but they use different engines.
The M240i has the B58, while the M3 uses the more powerful S58. As a result, the M3 has higher absolute power potential.
At MTR Performance, a BMW M3 G81 Competition with Stage 2, for example, delivered 650 hp — significantly more than the 470 hp of our M240i Stage 2 configuration.
However, the M240i has a strong argument: with 470 hp and 720 Nm the compact G42 offers a great deal of performance for its segment.
In short:
- M3: higher maximum power potential
- M240i: powerful B58, compact size, and excellent value for money
- M240i Stage 2: 470 hp and 720 Nm in our tested configuration
Also check out our BMW M3 G81 Competition Stage 2 project.
Does tuning affect the factory warranty?
Software and hardware modifications may affect the factory warranty or warranty claims.
The exact consequences depend on BMW's and the dealer's terms and conditions, as well as the nature of the modifications carried out. Therefore, always check in advance which conditions apply to your vehicle.
Frequently asked questions about BMW M240i G42 tuning
How much horsepower does a BMW M240i xDrive G42 have as standard?
The BMW M240i xDrive G42 produces 374 hp and 500 Nm.
How much horsepower can a BMW M240i G42 achieve with Stage 2?
In our own dyno measurement, the M240i G42 with our Stage 2 configuration delivered 470 hp and 720 Nm on RON98 fuel.
How much torque does a Stage 2 M240i deliver?
Our tested Stage 2 configuration delivered 720 Nm, compared with 500 Nm according to the factory specification.
How much horsepower does Stage 1 deliver on a BMW M240i G42?
Depending on the software, fuel, and hardware, a Stage 1 configuration typically produces around 450 hp. The exact result varies by car.
What is the difference between Stage 1 and Stage 2 on the M240i G42?
Stage 1 is primarily a software upgrade. With Stage 2, the ECU software is combined with additional performance hardware and, depending on the configuration, TCU tuning. Our tested Stage 2 configuration delivers 470 hp and 720 Nm.
Is TCU tuning needed for a Stage 2 M240i?
With our Stage 2 configuration, TCU tuning is part of the setup. The transmission software is adjusted to the higher engine torque and the revised ECU calibration.
Is an intercooler needed for Stage 2?
A performance intercooler is recommended when the car is used at higher power levels on a sustained basis, but it is not required. A more efficient intercooler helps keep intake air temperatures under control and can contribute to more stable performance.
What fuel does a tuned M240i need?
For our Stage 2 performance setups, we recommend RON98. The exact fuel requirements depend on the software calibration used.
Is the BMW M240i G42 suitable for tuning?
Yes. The B58 engine, xDrive drivetrain, and ZF 8-speed automatic transmission make the M240i G42 an interesting platform for performance tuning. As with any tuning configuration, maintenance, temperature management, and correct software calibration are important.
Conclusion: BMW M240i G42 tuning to 472 hp
The BMW M240i xDrive G42 starts with 374 hp and 500 Nm from the factory. With the right combination of software, hardware, fuel, and transmission calibration, significantly more is possible.
Our own Dynojet measurement shows what this means in practice: 470 hp and 720 Nm with our Stage 2 configuration on RON98.
This makes the M240i G42 a particularly interesting tuning platform for drivers who want more performance without immediately switching to an M3.
Would you like to know what is possible with your BMW M240i G42? Contact MTR Performance or view our BMW tuning projects for more cars and dyno results from our workshop in Rhoon.
