You may have noticed forged rims (and lug nuts) popping up on Honda and Acura performance cars everywhere. It’s a popular modification because it’s supposed to improve acceleration. Some of you may be hesitant to splurge on forged rims out of fear that the claim might not be legitimate. In fact, that’s probably why you’re here.
So the million dollar question here is: Do forged rims really improve acceleration? Let's discuss.
Most newer vehicles are equipped with aluminum wheels. Aluminum is a good material for wheels because it's a) lightweight and b) easy to form. With aluminum, automakers and aftermarket companies like Enkei or Rays can make interesting looking wheels that are light.
Lightness is important in wheels. Lighter wheels have a big impact in three areas:
On the first point - handling - the idea is pretty simple. It's harder to rotate a heavier mass than a lighter one. If you get a 25 lbs wheel going 60mph, and then decide to turn it, it will take a lot more effort than a 12 lbs wheel going the same speed.
On the second and third points, the idea is that a lighter wheel is easier to get spinning quickly and easier to stop. This makes intuitive sense, but a lot of auto enthusiasts wonder if lighter wheels make a big difference or not...how much difference could 10lbs of wheel weight really make, right?
Nearly 15 years ago, Hot Rod Magazine published an article showing that reducing wheel weight improved quarter mile times substantially. From the article:
We tested traditional rally wheels from Wheel Vintiques (which makes reproduction rallies in numerous sizes) against lightweight Center Line wheels on our 502-powered Mean Street Chevelle...with a total wheel weight reduction of about 20 lbs per wheel, our test car gained 1/10th of a second in the quarter mile
A tenth of a second in a quarter mile run isn't massive, but the test vehicle was equipped with a 502 cubic inch big block - an engine that massive generates a lot of torque. More than enough to handle some wheel weight.
Automakers frequently include forged wheels as standard equipment on supercars, like Acura did on the NSX back in 2002.
Another test from Car and Driver showed that reducing wheel weight made big improvements in acceleration for a Shelby GT350R:
Ford shaves 58 pounds from [all four wheels]...it’s hard to imagine that the mass of a bag and a half of dog food would radically alter performance, but...we noted a surprising difference in their acceleration times. Then we remembered that each wheel-and-tire assembly is effectively a flywheel that impedes acceleration and hampers braking
Again, this is on a vehicle with a big engine. If lighter wheels make a difference on these vehicles, imagine what they can do for a 4-cylinder engine with one half or even one third the torque.
Forged rims are manufactured using a more expensive process. While cast wheels are usually made by drawing aluminum into a vacuum mold - a standard process used for casting aluminum engine blocks, cylinder heads, etc. - manufacturing forged wheels is much more involved.
Forging used to be done by hand, carefully heating and hammering metal to make a specific shape.
Forged wheels are made by forcing a pure ingot of aluminum into a mold under extreme pressure and high heat. The process is expensive because of the energy used, and because the cost of the molds are much higher. However, the advantage in the process is that the finished wheel is much stronger than a cast wheel of the same size.
Because forged wheels are so much stronger, they can use less material...and therefore be lighter. Depending on the wheel, forging can save 10-20 lbs of weight over a cast aluminum wheel.
All of these brands offer forged wheels, and we carry products from each:
NOTE: If there's a wheel design you're looking for that you can't find on our site, please contact us. Wheel designs change quickly, and our website is not always able to keep up.