Hi
When I worked in motor sport I 'chipped' many cars (mainly Audi and VW) I cannot comment on the Peugeot and current results when chipping but certainly diesels produced more power when chipping than petrol cars there is a reason for this that would take volumes to explain. We never got that sort of percentage increase in power though and certainly in those days chip suppliers would 'dress up' their figures to sell the chips (they were more expensive in those days).
That said you do without a doubt get more power but it used to be at the cost of more fuel!
Any way I don't want to get bogged down in doubting people but one or two points of caution
First you will be told that chipping is not detectable and there is no need to tell insurance companies. Wrong. As I said I fitted loads, if you don't have an accident you are ok and most insurance assessors won't have a clue and you will get away with it. But trust me not all are and I have known many people come unstuck. More particularly with performance cars, granted, but none the less don't under-estimate them.
Secondly, and probably more importantly, the control units of cars, where the chips are fitted, are delicate when messed about with and not at all easy to work in. There is a high risk of subsequent break down and control unit failure often from dry or broken solder joints but also from poor quality chips. If your vehicle is recovered to a dealer they will detect a faulty control unit and replace it