He smartly said "Recovered 90hp" and not "made 90hp" It is all about energy efficiency in these power units.
Definitely the speed of the car would seem as it were 90 hp more powerful than last years one. Another thing to take from this 90hp recovery... If you look at the bigger picture... Mercedes has reached limiting returns. Many people said that last years Ferrari was about 80hp to 100hp down... Ferrari has recovered that over the winter they are right on the tail of Mercedes who as expected could not make that huge jump in power due to their engine having less headroom for improvment. I agree with Maurizio... next year is going to be very fun.