Unsprung weight

**skaria** · 06-13-2010, 07:55 AM

I read a lot about this on this forum and the extreme lengths my fellow forum members have gone to get wheels which are light -- stockers are pretty light to begin with: 21.5 lbs front / 24.5 lbs rear.

However, some recent events have made me more aware of another, less talked about component (with respect to unsprung weight), the tires. I thought I would share some of my findings:

Stock rubber (PZeros):
235/35/19: 22 lbs
295/30/19: 29 lbs

Michelin PS2s:
235/35/19: 22 lbs
295/30/19: 28 lbs

Hankook V12 Evo:
235/35/19: 24 lbs
295/30/19: 30 lbs

Pzero Rosso:
235/35/19: 24 lbs
295/30/19: 30 lbs

Yokohama Advan Sport:
235/35/19: 24 lbs
295/30/19: 30 lbs

Pirelli Corsas:
235/35/19: 20 lbs
295/30/19: 30 lbs

Hoosier A6 (track/competition)
235/35/19: 22 lbs
295/30/19: 25 lbs

In the 20" line, the Continentals are the lightest (21 lbs/26 lbs for 235/30/20 and 295/25/20 followed closely by the PS2s at 22 lbs/27 lbs). This research started when I got my HREs 19/20 with Pzero Nero tires:

new tires/HRE wheel/TPMS total weight:
235/35/19: 48.0 lbs
305/25/20: 56.7 lbs

half worn stock rubber/stock wheel/TPMS total weight:
235/35/19: 41.6 lbs
295/30/19: 51.6 lbs

Half way worn, the stock tires lost about 2 lbs of rubber since the should be 43.5 lbs/53.5 lbs new --(21.5 + 22 = 43.5 lbs front, 24.5 + 29 = 53.5 lbs). And yes, I am assuming zero weight for the TPMS mainly because it was already installed and I couldn't weigh them separately -- but they should be less than 0.5 lbs each.

Regards,

**harrison** · 06-13-2010, 11:42 AM

Dude, I have three track days on my Hoosiers and run them daily.They have an equivelant of 1,000 miles on them .They will DEFINITELY do another track day and plenty of canyoncarving and girl transporting.They are extremely lightweight I thought. And being half worn they are getting lighter. I think my tire wheel combo gives me the edge over my bigger, more powerful, mates' cars. BUT I have seen the tires of others' cars be ruined in one afternoon. I guess I am quite a bit more carefull than DESPARADO (and his son)...when it comes to the tires. (I am crazy in every other aspect). \"/ You might even say my life is SPRUNG...or UNSPRUNG as some might say !!!!!!!!!!!!!!!!!!!!! C-YAAAAAAAAAAAAAAAAAA !!!!!!!!!!!!!!!!!!