Do I go with 17 or 18's Options

[Drolius]

Hey guys...I can't decide whether to go w/ 17 or 18'' wheels. Please give me your input on this matter! Thanks.

[GeEkBoY]

The weight of the wheel has little effect, the amount of rotational inertia of the wheel is very small compared to the inertia of the car. Heavier wheels are detrimental to handling though as the unsprung weight increases and the suspension would therfore require stronger damping to compensate. Similar problems are found when you lower the car: the combination of stiffer springs that have much shorter travel without adding stonger damping causes you car to bounce up and down after a bump (like 99% of lowered civics out there).

The rim size does not affect speed, however the overall diameter of the wheel will change your drive ratio and therefore you acceleration. For example:
215-40-18 OD = 24.9"
205-55-15 (stock) OD = 24.0"

This changes you final ratio by about 4%. while not a big diference, it will slow down the car and your spedo will be off. Bigger wheels do look better though. If you want 18's with the same OD, 215-35-18 has the same OD, but you risk tire and rim damage with so little rubber.

Hope that helps.