So, 2 weeks ago I was heading out of Birmingham on the M6 on my way back to London, doing about 85. I started hearing a significant increase in road noise, and wondered if it was a tyre, but the car wasn't pulling left or right. Gave the wheel a wiggle - nothing untoward. The noise continued, so I decided to pull onto the hard shoulder and see what was occurring.

The front left tyre was toast. It was properly chewed, and was smoking. But the car wasn't bothered at all - no drama whatsoever. OK, it wasn't a blowout as such, but I was really impressed with how little effect a flat tyre had at that speed. So, good news if you ever have the same experience: the car is probably not going to dive into the barriers.

Of course, having no spare and it being 5:30 so no chance of a new tyre, even if I could find one, I had to complete my trip by low loader. Car is now fitted with two nice shiny new MPSS 265/35 front boots (down, CeeJay!).

 

Well, that was a potentially disastrous situation; it is comforting to know that the XK was stable under the circumstances, and this just increases my certainty that these are very safe cars.

 

Yep, and was it perchance a MPSS that blew up? I'd wager "yes" on that one...

 

So did the TPMS go off?

 

It might be time to invest in a spare wheel and tire. You can find them on Ebay here in the States. Maybe you can find them in the U K.

 

WRONG - Pzero. I'm not sure what the problem was - that tyre did have a very slow leak, and perhaps I simply didn't notice that it was flat or very low when I set off.

 

No TPMS on my car - wasn't even an option (the 75 didn't have any options, as far as I know). Starting to wonder if there's any way to retrofit it...

 

Probably can, but I'd also need spacers for the rear. I'm also not keen on losing the space in the well, or carrying the weight. But it's a fair point...

The issue was that I didn't notice until the tyre was thoroughly borked, so either of the repair options I have (can of goop and Dynaplug) were not viable. There were at least two 5 cm gashes in the sidewall. And I guess that is a situation I ought to be prepared for.

 

I don't know why one would want to ever fit these sensor on a vehicle I was looking to do the opposite

When driven hard my tpms go bizerk

 

Glad it all turned out safe and well. However, our impressions of tire damage and its effects often rely on Hollywood. In real life cars remain rather controllable, unless you happened to be cornering at max g-forces as the blowout occurred.

As a long time racing driver, we had blowouts on those ultra-light weight racing slicks and generally continued driving fast through turns in order to get to the pit for a tire change.

 

I would add, for the benefit of those of us with the 'donut spare' in the trunk, a cautionary tale and plea to check the tire pressure in that dumb thing. It's useless if it's flat, too.

How do I know this? I recently picked up a flat in the driver's side rear on a Sunday night approximately 4 miles north of a wide spot in the road called Brownsfield, TX. I figured I'd use the brand new portable air compressor to refill the tire and return to town looking for a spare, but no - that dang thing wouldn't work. So I pulled off the flat tire and mounted the donut. Flat as well from not having been checked since departing the factory in 2008. A quick "am I nuts, does this stupid brand new compressor REALLY not work" check (no), and it was time for a flatbed wrecker ride north to Laredo, TX for the night.

Got uber lucky and the Discount Tire operation in Laredo, TX had one in their warehouse and I was underway again by 10:30 the following morning. The donut held air just fine, per the service tech at their operation. I immediately bought a new (& improved) portable air compressor for the Jag trunk upon my return home.

My best efforts at preparation were for naught because I simply forgot to double check that tire pressure (and the working condition of the portable air compressor) prior to loading the trunk for vacation. Learn from my mistakes here, lads (and lassies).

 

I will add to the OP that a low pressure tire will heat up and eat itself quickly, especially at speed.

The doughnut spare is actually really light. I had mine out yesterday and I'd say it and the jack were less than 30 lbs. Surprisingly light.

 

If I was as skinny as a donut spare, I'd be lighter, too!