....wheel hp is a much more meaningful measurement, if you want to measure how much power actually gets transferred to the pavement. SAE bhp measurements are done on a dynamometer, on an engine equipped with all accessories. However, this does not take in to account losses throughout the drivetrain.

I would recommend that anyone planning mods run a baseline on a chassis dyno, then re-measure after adding parts if you want to be able to quantify any gains for the rest of us. This is common practice in the world of Sport Compacts.