If the owners manual for a 95 XJS 4.0 Convertible
lists the OEM tire - which it also came from the factory with, as a:
Pirelli P4000E 225/60ZR16 with the Dunlop SP2000 225/55ZR16
as an "alternative type/size"
So, for concours, if the BRAND of tire dosn't matter but the SIZE and SPEED RATING do. Will a 225/60 16 that is a V, W or Y speed rating be substituted
for a Z rated tire without a concours deduction?
Z rating is 149+
V rating is 149
W rating is 168
Y rating is 186
the AJ16 4.0 in an XJS convertible is "at most" a 147mph car
(according to the books) so one would think any of these could be
considered "comparable or superior equipment of original size and compatibility" right?
Mark Robertson
Jaguar Club of Florida
95 XJS 4.0 Convertible
Submitted by SW03-09811 on Wed, 03/24/2004 - 23:02
Mark,
JCNA does not now have a specific rule covering Speed Rating requirements except as may be inferred by the "replacement with comparable or superior equipment" statement that appears several times in the Rule Book when referring to tires.
The Judge's Concours Rules Committee (JCRC) is currently reviewing the content of Chapter 6. We intend to establish whether, after a Jaguar reaches a certain age, its tires will no longer be required to meet their original speed ratings, since many early tires are not being remanufactured to their original high standards.
Meanwhile, as a Judge, I would personally accept the replacement tires you propose using. While the original "Z" rating was supposedly 149+ mph, no one knows just how far above 149 it went. Therefore, I would consider a contemporary 149 mph "V" rated tire to be "comparable" to the original "Z" rating and both "W" and "Y" rated tires to be "superior".
Good luck
Dick Cavicke
Chair, JCRC