OBDI and OBDII
- Thread starter hky001
- Start date
OBDI went through the 1995 model year. The main difference is that OBDII is a far more restrictive onboard emissions control system that sacrifices power over OBDI. Put an OBDI system on an OBDII motor and you will get a significant power increase. The increase in displacement from the 325 to 328 and M3 3.0 vs. M3 3.2 was so the new OBDII engines would make the same amount of horsepower as their precedessors. The increased torque was an additional benefit of displacement.