Lexus ISF / IS-F / LFA / LF-A  Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter · #1 ·
I am inclined to buy the Vossen Wheels CV-3 ( it weight 28 ibs against OEM wheels 24ibs) because of the price but I am afraid that due to the additional weight of the machine will accelerate worse.

Who thinks that?

And 245/35 R20 front and 275/30 R20 rear will fit correctly? They recommend 245/30 and 285/25. Because i don't want to roll fenders but i will use KW3
 

·
Premium Member
Joined
·
154 Posts
f=ma or a = f/m. So if the vehicle weighs 3720 lbs stock and 3736 with the CV-3s, you'd be looking at a difference of 0.03%. In other words, yes, less acceleration but not noticeable. Handling on the track might be affected, but I can't speak to that - someone else on the board probably can.
 

·
Registered
Joined
·
6 Posts
There are many different sites where you can find the math behind this, but from what I have read, every pound of unsprung weight makes a much greater difference on vehicle performance than the rest of the vehicle weight.

So, going with heavier wheels isn't going to make a dramatic difference, but there will be a difference. Of course, everybody is interested in wheel weight, but usually nobody knows where that weight is concentrated. The more the weight is concentrated farther out from the center of the wheel, the more that weight will affect acceleration (i.e. light weight lug nuts won't make any difference at all because they are at the center of the rotating mass).

Also, along this same line of reasoning, the weight of the tire is more important that the weight of the wheel since the tire is located the farthest away from the center of the wheel and it's weight will affect the rotating mass the most.

Since you are looking at 20's, some of the wheel weight and all of the tire weight will be even farther away from the center of the wheel than with 19's, which will also further hinder acceleration...how much, I don't know. It will probably be very slight, but still noticeable.
 

·
Registered
Joined
·
15 Posts
The extra weight won't matter, it won't be noticeable at all. Depending on the tire you go with and it's inflation rate, you could see zero change.
 

·
LexusF.com Moderator
Joined
·
390 Posts
You will notice the difference. Unsprung weight is quite the enemy. Google "unsprung weight" to get a better idea of how that affects accel/decel, braking, handling, etc. The best weight reduction you can do no matter how small is in unsprung weight.
 

·
Registered
Joined
·
6 Posts
If you drive the everliving crap out of your car in the turns, you will probably notice a difference in feel. It will likely not be slower or faster though, unless it affects how the tire sits on the rim.

I have the feeling though, that you are far from a race driver, and would not notice, so with that, I say

Buy the wheel that you like the looks of and be happy.
 

·
Registered
Joined
·
3 Posts
So many uneducated people on this forum.

yes, 4 lbs per corner will be a big difference. please look up "unsprung" weight.
includes tires/wheels/lug nuts/rotors/calipers/knuckle/hub assemblies- it also includes a portion (roughly half) the weight of the axles/control arms and struts- these latter components are partially sprung and unsprung.


16 pounds on total weight of the car, no difference. 16 pounds in unsprung weight, big difference.

some of you guys will pay $3500 and buy lightweight forged wheels(including me since i was a volk whore for years) and brag how light they are but some of the same people will buy heavier wheels and say they dont make a difference. hypocrites i tell ya.

if you guys dont mind the F to feel less responsive, slower braking times and less peppy, then by all means, get heavier wheels.
 

·
Registered
Joined
·
18 Posts
It is said that every pound of unsprung weight is worth about 7 pounds of sprung weight. Will there be a difference at 4 lbs per wheel? yes, but you wont ever notice it on the street or the track unless you are a professional race car driver who is chasing the last few tenths of a second.
 

·
Registered
Joined
·
18 Posts
Also, yes the wheels weigh more, but its where the weight is located... if the weight is more towards the center then it will have far less of an impact.
 

·
Premium Member
Joined
·
712 Posts
^^^^You are so WRONG!!!! Did you miss the part about unsprung weight:confused:

Lou
 

·
Premium Member
Joined
·
712 Posts
^^^^Nine posts, all today:eek: But, you are incorrect:cool:

Lou
 
1 - 15 of 15 Posts
Top