Robert_K

iTrader: (1)

I see a lot of people saying the light the wheel the better. And while is basic statement form, yes, but not 100% true. Below you find a video from HRE Wheels explaining why and how a lightweight wheel benefits performance of your car.

.

Coprolite

Wheel manufacturers and distributors make it difficult to even determine wheel weights, never mind publish any kind of rotational inertia values. A lighter wheel will most likely have lower rotational inertia. Things get a little gray when weights are quite similar. A wheel that weighs 5% more might have lower rotational inertia.

Please note that I selected the % arbitrarily, as it is 21 lbs. vs 20 lbs. I don't even pretend to remember how to calculate or postulate on rotational inertia. Those college classes are too far in my past and the books are boxed.

Robert_K

iTrader: (1)

You bring up a good point though. A wheel weighing 21 lbs might have a lower rotational inertia than a wheel weighing 20lbs.

G37Sam

It's basically a function of the mass multiplied by how far that mass is from the center of rotation squared. Gets a little tricky when the mass is distributed (integration anyone?). Must keep the heavy parts of the wheel closer to the center.

/End nerd mode

soundmike

iTrader: (6)

And thus why it's good to factor your tire weights into the equation, as the weight will almost always be further out compared to wheels where the weight can be centered anywhere from the hub area to the lip.

I felt more of a difference shaving 4lbs off of tires, than i have taking the same amount of weight on wheels.

Coprolite

If I swap out wheels, I plan on finding the 3(or more) lightest and then pick the best one based upon looks and price. The tire choice will be similar and may even include all season, as this is my dd.

It would be interesting for someone to organize some sort of empirical testing of rims before mounting. I'd be willing to take part....

Robert_K

iTrader: (1)

I think for those on a budget the Enkei RPF1 are the "lightest" and best buy out there. Now my HRE P43SC are not for budget minded but did come in around 20-22lbs for my 19's.