I think I am going mad. (no don't answer that).

[The Natural Philosopher]

Last might I walked over to a friend of mine, and later on he ran me back in his car, when we discovered a rear tyre was nearly flat. I pumped it up with me trusty Halfords inflator, but I could hear air hissing out - we both did - and there was a draught coming out of the tread at one point. However it was dark so I left his car there, ran him home in mine, and this morning went out to see how flat the tyre was.

Well it wasn't. Flat. The hiss wasn't there, there was no sign of a hole..in the location where the air had been coming out (edge of the tread)...

WTF is going on? Rational explanations only please, no alcohol or hallucinogenic drugs were involved (sadly :(). He did run into his belligerent neighbours fence post yesterday though...would a spike through the tread self heal?

[John Rumm]

You might get a hole that only leaks above a certain pressure - so it would be worth checking the tyre pressure now and see if it matches what you put in it last night.

[Timothy Murphy]

Perhaps some of that rubber-solution-like material intended to mend small punctures had been inserted in the tyre at some point?

[whisky-dave]

deos ambient temp and pressure effect such things ?

[Adrian Caspersz]

Someone else's car....

[Lee]

Sometimes a tyre will leak in one position but not another, depends where the hole (if there is one) is and whether the flex of the tyre changes the shape of it as it rotates. It may also have become "detached" at the rim and then sealed itself again with the rotation. Had many a tyre over the years which would never leak while being used, but would if left a few days.

[GB]

A friend came round, complaining that the garage had just returned his car minus his cassette tapes. I asked him what his registration number was, went outside, and, sure enough, the garage had given him the wrong car.

[Lee]

Ah, must learn to read the post. I'd also go with the "different car" theory then :)

[michael adams]

The madness/mistake question should resolve itself as soon as he collects the car and agres to the state of the tyre..

Assuming that is, that the tyre doesn't decide to deflate again in the meantime.

In which case all bets are off.

michael adams

...

[Dave Plowman (News)]

Self repair fluid? Some makers use it.

[PeterC]

I've had a couple of bike tubes/tubular tyres that were OK when stationary but went down when rolling. In those cases it was the valve - on one, just moving the valve caused a hiss - but a car might have other causes. Also, as ahs been said, the hole might unseal/seal at various pressures.

[Jonno]

Dave Plowman (News) scribbled

He's about to discover it has only gone flat at the bottom.

[tabbypurr]

gaslighting!

NT

[Brian Gaff]

Are these those tyres which have a substance that hardens when the pressure drops, ie its a get you home thing, but not to be trusted long term. BMW seem to fit them on the new minis I understand, which begs the question, are new mini owners more likely to drive over nails than owners of other vehicles? Brian

[The Natural Philosopher]

Dunno. far as I know they are after-market fitment on this Honda accord

2.3 my mate has.

Wouldn't you want to put caltrops in the way of my Mini owner.

Mind you a little red number parked next to me at S/market today and out popped a dinky little brown number. Kerala I'd say.

Sigh. If I were 30 years younger...

[pamela]

LOL.

I've got that film on CD.

[Dennis Davis]

...

You are John Cleese [in the latest Specsavers TV ad] and I claim my five pounds[1].

...yes, I know the door is over there. I'll get my coat and leave...

[1]

[ARW]

I once did that with a Citroen Berlingo. I had a massive hangover and I got in the wrong van and set off to drive to the wholesalers for parts.

Christ knows how the keys fitted both vans.