Are online OBD fuel savers useful?

[MacSarah]

Online OBD fuel savers are not effective, and here are the reasons: 1. OBD fuel savers basically cannot modify the core data of the vehicle's ECU. 2. Flashing the car's ECU requires professional computer programs and experimental models to simulate the data. OBD fuel savers can only receive and send signals and data, but cannot decrypt the manufacturer's encrypted data, so they actually have no fuel-saving effect. 3. Even if OBD fuel savers were useful, the adjusted data might affect the normal operation of the engine. If the adjusted fuel injection volume is insufficient, it could lead to insufficient power. If it's too rich, it could increase carbon deposits. If the ignition timing angle is too small, the power would be poor, and if it's too large, it could cause knocking and cylinder scoring.