The trees of Sussex collectively go
16V means (for a 4 cylinder engine) 4 valves per cylinder (2 inlet and 2 exhaust) the biggest advantage being it allows more fuel/air mixture in and more exhaust out (because a bigger area is opened) so getting more power per cc IIRC especially at higher revs
You also get advantages is spark plug positioning and shorter valve open time which improve power and there is allegedly reduced cam wear but you lose some power as more valve work is required
There must be a Wiki article on it, there is on everything else
