Not that I know much about tyres but....
We bought four new hydrogen filled tyres at Costco a couple of years ago and hardly drive anywhere so they should have lasted a while.

We had the car serviced a few weeks ago by our usual guy who comes to the house and he rotated the tyres, you know sort of crossed them over...front right to rear left and front left to rear right as we always have. Anyway we drove past a building site last week and got four roofing nails in a tyre! We were near Costco so we went to have them sorted out. Expecting a bill, we found out that if you buy tyres from them the rotation and any repairs are FREE!

Great! Though we were on a winner here...but the guy said that because the tyres had been crossed over they had badly worn and should only be changed in a straight line back to front not diagonally. Of course they hadn't told us of this when we bought them1

Another expensive lesson learned!:curse:

You mean "tires"!!

That's just a rumor! Tried doing crosswords over here?

Sounds like BS to me! Why is it called ROTATION and not LINEAR TRANSFER?

The Nitrogen filling is also BS. Air is mostly nitrogen. In order to fill the tire with nitrogen they'd have to suck every bit of air out of a tire - that wuold break the "bead." So you actually have air and nitrogen in your tire. And then when you top up with air your ratios start to approach normal air again. It's just another way for them to make money by "adding value."

Tires get worn because they are either over or underinflated, or beacause they toe-in or toe-out beyond the specs for the tire and the car. You rotate the tires to even out the wear. Keeping them properly inflated lengthens life too...... as does not driving over nails!

http://www.tirerack.com/tires/tirete...jsp?techid=43&

I certainly hope not. Gives the term "banger" a whole new dimension.

OH's just come in - NITROGEN!!

We fill up with nitrogen when we need to at Cosco - we go every two weeks to shop so it's no hassle.

Absolutely. I heard some idiot "tire expert" on TV last week explaining that since nitrogen is heavier than oxygen or air, it diffuses out more slowly and helps keep the inflation pressure in range.

Two things, dork "tire expert": periodic table and Fick's Law of Diffusion.

Well they don't rotate these tyres they do linear transfer if you like to call it that! The tyres have a directional mark on them showing how to do it - wish our guy had spotted that !

I too have tyres filled with rhododendrons (it's a Beetle). One went soft so I filled it with air. Today I took it back to the dealer, explained the situation and asked them to fix it. They couldn't find the leak but were very proud of having replaced the air with gas to match the other tyres. I wondered though, gases and pressures and all, if the tyres are supposed to be inflated to 30lbs psi and that assumes air, should it be a different pressure for another gas?

Right - we have same size directional tyres.

There's lots on the web for and against but here's Costo's page anyhow.

http://www.costcoconnection.com/conn.../200410/?pg=17

No worries there. As long as the gas in question is a homonuclear diatomic, (eg N2, O2 or air, which is a mixture of both) then there is no difference at all in the temperature-pressure thingy (even in Fahrenheit and pounds per square inch).

N2 though is (despite the dork referred to above), slightly lighter and more diffusive than either O2 or air. So if anything, you'd have to reinflate more often, not less. And of course for more $$. Who'd have guessed?

For best performance, I insist on a custom blend: 78% Nitrogen, 21% Oxygen, 0.93% Argon, 0.04% Carbon Dioxide, plus trace gasses.

Never had a problem finding it, and no complaints about how well it works.

Note that I wasn't making an effort there, tyre air pressure, like the size of people and the price of meat, is something that's usually measured in imperial in Ontario. I've no idea how metric tyre pressures would be expressed; is it joules per 100 rotations?

I have a quibble. It should be gases. And of course in the US a great deal more sulfur dioxide than in Ontario.