2017 Polaris Sportsman New HP Leader

The 2017 sportsman 1000 has 90 HP compared to the Outlander 89 HP. Funny thing is Polaris has 4 1000cc atv’s all four have a different HP….

Sportsman 1000 90HP
Scrambler 1000 89HP
Sportsman Touring 1000 88HP
Sportsman Highlifter 1000 85HP

Correct me if I am wrong but all Can-am atv 1000 engines have the same hp. How or why does Polaris do this? Different tunes? I just thought this was interesting and also how Can-am is no longer the hp leader…..