Tuning Box: Save 1L Fuel Per Trip

Hello,

A few days ago, I received a tuning box from an acquaintance. After connecting the box, I was thrilled with the increased power. But I'm even more excited about my fuel consumption. It has decreased by a liter on my daily route, which includes highway, city driving, and a mountain road. According to my MFA (Multi Function Display), it went from 5.5 liters to 4.2 liters per 100 km. At times, it even showed 3.5 liters.

Now, my question:
Does the box distort the consumption data? Or is it impossible to deceive the MFA (Multi-Factor Authentication)?

What about the compatibility with the engine?
Have you had any bad experiences that you can definitely attribute to a tuning box?

Car:
Volkswagen Golf III GTI TDI AFN, 81 kW.

Best regards, Nico.

Hi!
Please use the search function! This topic has been discussed so many times here that no one will likely respond to it again.

Best regards,

Hi,

Regarding the side effects of the medication, please refer to Brezelmann's response.

Regarding consumption: This type of device works by manipulating sensor data, in this case, the amount of fuel injected. As a result, the engine control unit (ECU) "believes" that it is injecting too little fuel and increases the injection amount accordingly.

The consumption calculation is based on what the MSG "knows." In other words, you can ignore the MFA display.

Best regards,

Jan.