Csaba wrote:___________________________________________
Most of your points are valid, but I would point out a few arguments in my
defense.
OK…
Most tire manufacturers will warrant their tires for a period of at least
seven years. Given our litigious society, this is likely to be a rock-solid
safe life expectancy under the absolutely worst conditions
Maybe tyre technology has advanced to the point where 7 years is now a
reasonable life expectency. Having said that, aren’t your tyres 2 or 3
times older than that? It necessarily follows that if they are indeed 15+
years old, they were made at a time prior to the amazing technological
advantages held by current manufacturers.
Additionally, I think you will find that a manufacturer’s warranty is
likely to talk about ‘tread wear’.
In the manufacturing and retail industry it is a fact that warranties are
rarely called in. On the occasions that they are, the manufacturer is
normally protected by the proverbial ‘small print’.
An example of how a manufacturer can use a warranty as a marketing tool is
in the case of perhaps the biggest manufacturer of video tapes in the
world. I don’t recall the exact statistical analysis that was done, but the
point remains clear. The manufacturer realized that the average video tape,
used in the average household for an average number of recordings would
last about 2 years before it started to malfunction. The company had the
technology and expertise within its research personnel to develop a tape
that would last perhaps 10 years. Rather than the spend the vast fortunes
such research would apparently have cost to conduct, they decided to simply
change the warranty from 12 months to a lifetime guarantee. They worked on
the premise that after a couple of years, 99% of consumers would not take a
video tape back and claim on the warranty. They changed their advertising
to reflect the ‘incredible longevity’ of the ‘new’ tape (and the lifetime
guarantee) - and sales quadrupled.
Besides, when I think about old tires and their safety, I always recall a
trip to Bonneville Speedweek about five years ago, where I saw Al Teague,
the
current wheel-driven land speed record holder (409 mph and change), and saw
him make a one-way pass at over 400 mph. Even standing a quarter-mile back
from the course, it was incredibly fast. At the end of the run, I examined
the car closely, and noticed that the tires where quite shredded. At least
one of the twenty plies on each tire had come apart, cloaking the tire in a
curtain of cotton fibers that looked like a bad toupee.
Turns out Teague runs his car on Firestone Land Speed record tires built in
1970! For liability reasons, Firestone and Goodyear got out of the record
tire business after that. so Teague pursues his records on these nearly
thirty-year-old gumballs. When Teague saw my mouth drop open as he
explained
this he told me not to worry. After each run, he just cuts of the
delaminated
ply with a razor and runs the tire again and again!
Later, one of the grizzled Bonneville old-timers confirmed every bit of
Teague’s story. When I asked if the tires hadn’t hardened with age, he
answered “Harder than a wedding night dick.”
In this context, my slight flirtation with my old tires pales into
insignificance.
Great story, but alas I don’t buy it in terms of negating or minimizing the
risks you are taking. Dead is dead whether the automobile was traveling at
90 mph or 400 mph. Remember too that the colourful Mr. Teague has very
little traffic to deal with during an ‘incident’ on the salt flats. His
story reminds of the 90 year old man who has smoked every day of his life
since he was 10 and never had a day off work…I’m sure you get my
point…
Even so, I will replace my tires in the near future, though probably not
with
the Pirellis you mentioned. The 4000s you mentioned are 205/70-15s and too
wide for the five-inch rims on early E-types. In fact, there are precious
few
H or V-rated radials available in the original 185-15 size without going to
an old tire specialist and spending $160-200 apiece for old-style Michelins
or Dunlops.
Which of these tires would you suggest, from the lofty height of your
soapbox?
Glad to hear they are about to be changed. Some tyres to consider might be
as follows:
Yokohama A321 185/70 (V, I think)
Michelin 185/70VR XWXT (V)
Michelin 195/70 XWV4 (H rated, I think)
Dunlop SP4 185/75 (V)
H = 112mph
T = 118mph
V = 149mph
I don’t mean to preach, Csaba, but I believe this a really serious issue. I
have kicked my soap box into the corner and promise to leave it there 
Regards,
Dan Mooney
@Dan_Mooney
http://www.classicjaguar.com
