Lightweight Wheels - Does it really matter?

[jflogerzi]

I would not chase after the lowest weight for wheels. Get something that works for what your objectives are, budget, and from a reliable manufacture.

[Vracer111]

Only saw one person give the answer, but the main reason for reducing unsprung mass is to allow the suspension to perform better and not upset the chassis so much because of inconsistencies in the road surface - you will notice a Huge improvement in ride quality, stability, and agility with a 4-5lb reduction in unsprung mass per corner. I'd much rather keep the stock tires and drop 5lbs a corner than up the grip and keep the mass nearly the same as stock weight.

But you can also drop the same weight while going with stickier same sized or slightly smaller tires... I'll take moving up to a stickier compound of stock sized or smaller/lighter tire over doing the same but increasing width/size in the process for daily driver. The best lightweight wheel designs have lots of smaller, thinner spokes - the more spokes the better (distribution of forces acting on the wheel rim/barrel).

[DarkSunrise]

Interesting comparison of stock vs. lightweight wheels (-7 lbs/ea) on a Ford Focus here:

http://www.focusst.org/forum/attachm...wheel-test.pdf

4s/lap seems like a huge difference for just lighter wheels, but I do like that they used average laptimes for the comparison.

[Yoniyama]

The unsprung weight (wheel, tire, brake, spring, strut/shocks, hub, suspension links, etc) is nearly 100lb per corner in the front, and about 90lb per corner in the rear. Therefore, reducing the unsprung weight by only three, four lb per corner can hardly be felt. (You would do this primarily for changing appearance, and not for any preformance improvement.)

I have a set of Enkei RPF-1 16x7 running on 18lb 205/55-16 tires, and 2-piece front brake rotors (saving another 5lb each). I also use Muteki open-end lug-nuts, each weighs only 25 grammes. In my case, the reduction in unsprung weight is noticeable, and for the better. With OEM springs and shocks, and lighter (Cusco) anti-roll bars, the car drives more like a classic Alfa or Lancia: much more finesse than brute power.

But if you up-size the wheels to 18" and run super-wide tires (225 or more), the deterioration in handling, ride comfort, and acceleration may be quite

[team3d]

fast ford magazine did a test on stock wheels vs light weight wheels...

here is a pdf link for the article

http://www.focusst.org/forum/attach...ghtweight-wheel-test-fast-ford-wheel-test.pdf

[team3d]

davenport motorsport also did a dyno for hre wheels...

Dyno Runs - The effects of wheel/tire weights on wheel horsepower Test:
Davenport Motorsports (www.davenportmotorsports.com) of Canada, wanted to see the dyno effects of running different wheels on cars. They took a factory [ame="http://www.amazon.com/dp/B008VIRAXI"]2012 Camaro[/ame] SS and ran 3 dyno runs. They ran the first run with a set of [ame="http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=271&BEFID=96477&acode=281&code=28 1&aon=&crawler_id=1929692&dealId=6Z1QWReM50JkvJuRD CecGA%3D%3D&searchID=&url=http%3A%2F%2Frover.ebay. com%2Frover%2F1%2F711-57618-1854-0%2F2%3Fkwid%3D1%26mtid%3D570%26crlp%3D1_240251%26 linkin_id%3D%7Blinkin_id%7D%26sortbid%3D%7Bbidamou nt%7D%26fitem%3D310381695763%26mt_id%3D570%26mpre% 3Dhttp%253A%252F%252Fwww.ebay.com%252Fitm%252Flike %252F310381695763%26mid%3D503280%26sdc_id%3D%7Bsdc _id%7D&DealName=73-66.6%20Metal%20Hubcentric%20Hub%20Centric%20Rings% 20Ring%20Set%20Aftermarket%20Wheels%20Rims&Merchan tID=503280&HasLink=yes&category=0&AR=-1&NG=1&GR=1&ND=1&PN=1&RR=-1&ST=&MN=msnFeed&FPT=SDCF&NDS=1&NMS=1&NDP=1&MRS=&P D=0&brnId=2455&lnkId=8070676&Issdt=150208050355&Is Ftr=0&IsSmart=0&dlprc=17.5&SKU=310381695763"]aftermarket wheels[/ame], the 2nd run with a set of stock factory wheels and the 3rd run with a set of HRE P45S wheels, all in 20” sizes.

These results highlight the effects of rotational inertia on drive-train losses (the hp lost between the engine crank and the ground). Wheels and tires contribute to drive-train losses as energy is used to spin up the wheels (and decelerate the wheels under braking). From the dyno chart you can see the effect of replacing factory wheels with lighter HRE wheels and see the negative effects of installing heavier aftermarket wheels.

Results:
1. (Blue curve) Factory wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 68 lbs combined per rear wheel. – Max hp: 371 hp, Max Torque: 375 ftlbs - (Baseline)
2. (Red curve) Aftermarket wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 72 lbs combined per rear wheel – Max hp: 369 hp, Max Torque: 373 ftlbs - (A [-] loss of 2 hp and 2 ftlbs)
3. (Green curve) HRE wheels: 20”x11.0” with Nitto 315/35-20 tires weighing 60 lbs combined per rear wheel – Max hp: 380hp, Max Torque: 384 ftlbs - (A [+] gain of 8 hp and 9 ftlbs and that is running a 2” wider wheel/tire combo)

Conclusion:
The engine obviously still cranks out the same amount of hp and torque, the lighter HREs simply waste less of it before it gets to the ground. Also interesting to note is that the gains are not just peak gains, but gains across the entire rev range. If they had done a braking test, we would have seen similar results as the rotational inertia effects also have a significant effect on how much energy is used to stop the wheel/tire combo vs. stopping the car. We talk about these effects all the time and focus on designing lightweight wheels with low rotational inertia, but it isn’t every day that you get to see real hard data showing the true effects.


Dyno Run - Effects of wheel/tire weights on wheel horsepower by HRE Wheels, on Flickr

Read more: http://mbworld.org/forums/c63-amg-w2...#ixzz3RDEtUMI7

[Kostamojen]

Anyone who has gone to "large" wheels can assure you they do slow the car down. Its instantly noticeable.

I can't wait to go back down to 16's from my 18's and shave some 12lbs off the tire/wheel weight combo Should be fun.

[toyota_86]

This is a good video showing the impact on acceleration time of heavier wheels.

[x808drifter]

Originally Posted by toyota_86

This is a good video showing the impact on acceleration time of heavier wheels.

Thank you for bumping a nearly decade old thread with a 4 year old video saying the same thing we already said...