OBD-II was introduced mainly to address concerns about vehicle emissions and environmental pollution, as well as to standardize diagnostics for better vehicle maintenance and safety. The system was mandated as part of stricter environmental regulations to ensure vehicles constantly monitor their emissions systems. By detecting issues in components that affect emissions—such as catalytic converters and oxygen sensors—and alerting drivers to these problems, OBD-II helps keep emissions within regulated limits throughout a vehicle's lifespan. This system has been crucial in addressing air quality concerns, especially in densely populated urban areas.

For manufacturers, data reveals insights into an OEM’s intellectual property (IP) and design strategies, which they are keen to protect. To secure this data, OEMs implement cybersecurity measures over CAN or Ethernet networks and vigilantly monitor for any vulnerabilities. 

However, there are a few ways to access vehicle data. One approach is data reverse engineering, a time-consuming and complex process that provides limited data with no guaranteed results. On the plus side, data can be collected at a good sampling rate, depending on the ECU architecture. Another method is to log data by instrumenting the vehicle, which allows data to be captured at any desired sampling rate. However, this method is costly, time-consuming, and often faces challenges related to data noise and reliability.

Here is where OBDII becomes relevant. It offers a quick and straightforward way to access data from a vehicle. Under OBD legislation, on-demand data logging is possible by requesting specific commands from the ECU. Nearly 200 parameters related to emissions and engine function can be logged on request, making this a robust data-logging method that requires minimal preparation. However, there are drawbacks. Since OBD-II data logging is request-based, it cannot record data at very high frequencies. Additionally, while nearly 200 parameters are legislated, manufacturers typically permit access to only 20–30 parameters, and ECUs are programmed to log just these parameters. Furthermore, there is a trade-off between the number of parameters logged and the sampling rate; as the number of logged parameters increases, the sampling rate decreases.

Data security is critical for OEMs, as they seek to protect their IP from exposure. At the same time, competitors often try to access each other’s vehicle data. To log data from competitor vehicles, OEMs use a combination of data acquisition methods. While OBD-II was initially introduced for emissions-related diagnostics and data logging, it is now widely used in the industry to benchmark competitor vehicles and extract valuable performance data.