Quote:
Originally Posted by YeeFit
I figured I'd ask the more rev happy ppl in this forum to see if they have any insight on wheel weights and how they affect our cars.
I understand that the current Fit Sport rims weigh 15.8lbs roughly.. now I have been contemplating getting 17" wheels that weigh 18lbs. I know that isn't much of a difference, but the wheels I am also considering are a set of 15" 10.6lb wheels.
So the difference in weight between the 2 different wheels that I am considering is 7.4lbs.
Now this could be a pretty big number when it comes to how my Fit will perform seeing as we are just rated above 100hp...
Can someone fill me in with their knowledge? what are the advantages and disadvantages?
I'm not going to track my car, but I do like to drive aggressively and don't want to make my Fit any slower than it already is.  |
The weight of the wheels matter of course as it takes more power to accelerate the added 2.2 lb per wheel. 18 lb minus 15.8 lb is 2.2 lb.
However, thats only half the story.
Because the tire weight is further from the axle their centrifigal force is much greater than that of the wheel. If you save 2 lb on the weight of the tire you will end up with the same total weight but with the center of gravity now closer to the axle. And that means your Fit will accelerate faster. CF=mvv/r.
To 'solve' your question compare the addition of centrifugal forces of both tires and wheels.
If you subtract 5 lb per wheel and add 4.2 lb per tire and use 7" for the radius of the wheel and 11" for the tire radius what happens?
Its like stopping a spinning big tire vs a small light tire the same diameter.
And thats why as you increase tire width you should slightly decrease tire diameter. The less weight further from the axle the easier it is to spin the tire faster. To make up for more weight & rolling friction