View Single Post
Old 04-06-2013, 01:04 PM   #38
ZDan
Senior Member
 
ZDan's Avatar
 
Join Date: May 2011
Drives: '23 BRZ
Location: Providence, RI
Posts: 4,672
Thanks: 1,439
Thanked 4,011 Times in 2,097 Posts
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by hal0n View Post
I didn't see this mentioned. Another thing to consider is that the rotating mass stores energy. This is just like the flywheel. There are some situations where reducing rotating mass can hurt performance such as climbing hills. In general the trade offs are completely worth it though.
Only if you allow the car to slow down going up the hill. They you get a TINY smidge of "assistance", and you'll coast *slightly* further. If you maintain speed, zero difference. If you try to accelerate, of course you'll be slightly slower with the heavier wheels.

Already mentioned previously, but the rotational energy in the wheel is not that significant relative to the tire. I also had calculated 1.7x as the effective *tire* weight savings multiplier which I've used in vehicle performance modeling for years. Someone else in this thread came up with 1.25x for wheels as a general factor, which seems plausible, but since that's so small I just leave it out.
ZDan is offline   Reply With Quote