Don't fault car manufacturers for their power specs. They don't state the numbers whichever way it "looks better". It ALWAYS "looks better" to state engine output rather than driven-wheels output, but it's also more meaningful, too. Anyway, it's not up to the manufacturer how to do it, it's up to the Society of Automotive Engineers (aka, SAE). That abbreviation probably looks familiar to most people - they also set standards for fuels, oils, hydraulic fluids, etc. It's better to have an independent body of experts set the rules rather than each competing manufacturer doing it differently. SAE defines standard test procedures and conditions, so that each manufacturer's claims can be meaningfully compared.

Can you imagine the mess it would be to understand power output when the same engine was installed in two different cars with different drive trains? They would be rated totally differently in a 2WD vs an AWD car.

Anyway, throwing your car on a Dynometer isn't exactly compliant with the SAE test procedure, and there are dozens of uncontrolled variables, so two runs on two different days will give you two very different graphs, and peak power ratings (at the wheels) that could easily vary +/- 20% for the SAME CAR in the SAME CONFIGURATION, so you have to take that data with a pretty big grain of salt. What is representative of one car on one day is not going to be representative of a different car on another day.

Which is all summarized by my new tag-line...

EVERYTHING is ALWAYS more complicated.