GenVibe - Community for Pontiac Vibe Enthusiasts

I've been told by a few people that if you increase your wheel Size you will lose some hp just wondering if anybody can tell me if that's true or how secnifacant the loss is?

I'm sorry to inform you that this information is SOOO False. You have more rotating mass to move, so, this may make the car seem slower.Inder

if its heavier wheel.then its take more power to turn.but i think the biggest factor is a larger size changes gearing.if you stay wh plus sizing and your wheels aret lead.the difference should be negligible.

Expanding on satur9's answer, bigger/heavier wheels have more rotational inertia, so even if the outside diameter and thus the effective gearing of the vehicle is the same, they will reduce vehicle acceleration. The weight increase will have about twice the effect as just carrying the same additional mass in the vehicle, as they have to be spun up like a flywheel as well as being moved along the road. Heavier wheels don't change the actual engine power of course, but the very popular Dynojet and similar design chassis dynamometers are inertia devices, that is they calculate HP based on how quickly the engine can accelerate a very heavy flywheel/roller. Since heavier wheels act as additional flywheel mass when accelerating, such a dyno will show lower HP with them.