@nytro
Sorry buddy i wasn't doubting your skils of comprehension, i was actually trying to convey some info but i wasn't too sure if i did a good job that's why i wrote the last line. Wasn't trying to offend you in any way.
NEXT!
Low profile tyres:
Obviously if you wish to keep your rolling diameter correct you'll have to either fit a wider tyre with a lower profile on your existing rims or a larger diameter rim with lower profile tyres. when doing either you are increasing your unsprung weight (in 99.9% of the cases) which will put more load on your wheel bearings and require more power to rotate them so in fact low profile tyres (either way) will slow your 0-62mp/h (0-100km/h) runs. on the plus side you will gain more in terms of handling due to the lower sidewall height.
I should point out that there is a limit to the size required for all cars.
the 1996 honda civic had small 14 inch tyres as standard and currently most people fit 17's to it which indeed does look good but there is little benefit of fitting 17's since all they do is slow the car down and not gaining any benefits on lateral grip when comapred to 16's (as well as a harsh ride).
If you were to fit 205/45R16's to the 96-99 civic you'll find that they were the exact size fitted to the same civic type-S and type-R and there was a reason beind that. Honda did research into the rim size and found that after 16's they were not gaining any real benefits and were only slowing hte car down while increasing the unsprung weight (and making the ride harsher). Personally i dont believe in going past factory specs with my rim/tyre packages and the standard nowdays is to pus size by 2 inches on the rims, no more.