I drive a second-hand 2005 BMW X3, which I got in university, and in 2020 I took it to have the ECU (Engine Control Unit) tuned.
Although my X3’s 2.0-litre, turbo-diesel engine came with ample power, I was not satisfied and wanted more.
Before deciding on an ECU tune, however, I did a ton of research on potential modifications.
I found that while exhaust modifications provide good power, they can be costly and need to run alongside an ECU tune for maximum benefit.
Cold air intakes, while on the cheaper side, only allow for a small increase in power.
The best balance, for me, was an ECU tune which, according to DTE Systems, can provide up to 30% more power.
How it works
An ECU tune works by reprogramming the car’s Engine Control Unit. This manages the inputs of the engine, such as fuel flow and ignition timing.
When cars are built, manufacturers tend not to push the engines to their maximum potential – instead opting to dial back the engine’s maximum performance for increased reliability and fuel efficiency.
By adjusting the ignition timing, air-fuel ratio, and boost provided by the turbo, this potential can be unlocked to achieve better performance.
Getting the ECU tune was also easy.
I took my car to a local tuning shop where a technician connected his equipment to the on-board diagnostics port, which allows access to the car’s ECU, and replaced the stock file with a modified one.
This modified file was bought from a tuning company based in the UK, which I was told is common practice as creating your own tunes can be expensive and time-consuming.
It took about 30 minutes to upload the file and check that everything was running as it should.
My car was producing 110kW before the tune, and afterwards this increased to 130kW.
Torque was also increased from around 330Nm to 390Nm.
This increase in power has made a notable improvement in the car’s acceleration, and the extra torque has improved the car’s responsiveness.
This allows me to drive in higher gears for better fuel efficiency, and my fuel efficiency has improved by around 0.5-litres/100km since the tune.
It must be noted that if not done correctly, an ECU tune could cause a loss of power, increase engine wear, or even destroy the car’s engine.
Fortunately, many tuning shops do offer warranties on their ECU tunes in case something goes wrong
These warranties can differ in the years they run for and the amount offered.
It must also be noted that an ECU tune can have an impact on your manufacturer’s warranty and service plan.
The price of my ECU tune was R3,500 – but you can expect to pay more for custom tunes or for the ability to switch between tunes through a remote or phone app.