anyone know the benifits of lightweight wheels?

[fu_im_from_texas]

Originally Posted by CaysE

...fu, the weights of the wheels themselves could've told you the same thing without going through all that calculation. 10 lb wheels are 33% lighter than 15lb wheels, thus requiring 33% less energy to move them....

CaysE, You are right!...This is only true for the simplest case, which I examined here. If we concidered the case of 17inch 10lb rims, then the moment of inerti would be larger...the moment of inerta grows exponentialy with the radius of the rim.

Originally Posted by CaysE

Cliffs notes: you're only looking at half the picture.

Can you please provide a calculation for the other half of the picture?

Originally Posted by Biggie™

...You are comparing the amount of energy while driving at 60 mph, not the amount of energy it took to actually accelerate the extra 20 pounds of wheels...

Biggie, This is false. When the car is going 0mph the energy is 0. When the car is going 60mph the energy is about 4xxx kW. The difference, or amount of energy it takes to accellerate the mass is 4xxx-0 = 4xxx kW

Originally Posted by Biggie™

...
Also you didn't factor the rotational weight effects. You just treated the wheels as a non independent part of a mass that is the car....

The first portion of my calculation was the rotational effects...

One error I do see is I compaired the energy of 1 wheel, when there are 4 on a car....multipling the energy of 1 wheel x 4 still nets a neglegable ammount of energy...

Can anyone provide an alternate calculation?