09-02-2008, 05:43 AM
Based upon my experience and feeling on tire longevity, I would be concerned about running the 1999 tire at speed, and would not use the 1989 tire, period.
I have seen too much deterioration in relatively new tires to risk running old ones. Though not directly related, I have seen other types of tires deteriorate very quickly, i.e. bicycle tires. I have had them dry-rot just hanging inside a heated garage for only a few years. In fact, I just got a flat yesterday when a tube ruptured inside of the tire. There was no external damage to the tire, and the carcass was smooth and 100% intact. The tube inside had lost it's elasticity and just blew.
I have seen too much deterioration in relatively new tires to risk running old ones. Though not directly related, I have seen other types of tires deteriorate very quickly, i.e. bicycle tires. I have had them dry-rot just hanging inside a heated garage for only a few years. In fact, I just got a flat yesterday when a tube ruptured inside of the tire. There was no external damage to the tire, and the carcass was smooth and 100% intact. The tube inside had lost it's elasticity and just blew.
Larry Herman
2006 Cayenne S
2010 Allegro RED 38QBA
Nationally Certified PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
2006 Cayenne S
2010 Allegro RED 38QBA
Nationally Certified PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car