Turbo overboost

I was browsing Wind reviews the other day an Honest John's article included this bit:

"The turbo also has an overboost function which increases power by 5PS and 6Nm of torque in second, third and fourth gears at speeds above 4500rpm."

Ive not heard any mention of this anywhere else (and not noticed it while driving).

Anyone else heard about it?

My twingo had the same thing in its brochure

Not having the 1.2 turbo I would guess, and it is a guess, that you would not notice a 5PS increase if you are hammering along at above 4500 revs, considering the car only has 98 BHP.

PS = 98.6% of a brake horsepower, so for 5PS your talking 4.93 BHP, not enough to be significantly noticable.