Imports over rate their engines. Hyundai and Volkswagen I believe got into trouble for overrating the Tiburon and TDI more than they really were.

It's sad they have to lie to keep up with Detroit.
Regadless, it doesn't matter what the measurements are, so long as manufacturers aren't forced to actually change the output of their engines.
The new calculations could cause them to say 20HP, but it's the same exact engine as when it was rated at 270HP, what's really the difference besides bragging rights.