The practice of diagonal wheel changing to even out tyre wear went out of fashion in the 70/80's in the UK.

as it did over here. Since all of my tires, not tyres, have directional treads that would be very expensive anyway due to the cost of remounting the tires on the rims.

Bias ply tires are a long ago thing. Good riddance.

With modern cars with independent suspension wheel changing simply isn't necessary.

Then why did you get uneven tyre wear?

Caster, Camber, Toe, Balance, inflation

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Caster, Camber, Toe, Balance, inflation

Three of the four were evenly out of spec?

Caster, Camber, Toe, Balance, inflation

Three of the four were evenly out of spec?

Who knows, I just provided the list of excuses.

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Balance is important on the steering wheels to avod speed shudder, not so important on the rear.

Please tell that to any F1 , NASCAR , INDI , GP2 , F3 etc team , Mclarren are "just up t road" from you and the way their season's going again :-( could do with all the help they can get ;-) ( still support em tho even if my moneys on Merc and Lewis for this season ( Roll on Spa :-) :-) :-) )

Apparently Chris hasn't seen a rear out of balance. When the tire spends half the time not in contact with the road braking effectiveness is rather reduced. Shock absorbers can only do so much. Of course the bald spot where it hits the road every time around also causes issues on wet pavement.

As to rotation, the cross pattern went out with bias belt tires which did not have an arrow on the side wall with a rotation direction. Rotation, front to rear on the same side is now the pattern.

As to wearing them all out at once, that is the reason for rotation. Get the most out of a set. After all it isn't a good idea to have different diameter tires on either. (Unless you are doing circles on a race track)

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As to wearing them all out at once, that is the reason for rotation. Get the most out of a set. After all it isn't a good idea to have different diameter tires on either.

Gary I'm totally with you on that one.

You really don't know much about vehicles and tyres do you?

Chris I do know a lot about autos and rotating front to rear will allow you to use up all the tread that you paid for, have better balanced handling and breaking. As for your car something is wrong when 3 are worn enough to merit replacement and the 4th is OK. Even if you did replace the tires with the same make and model as the survivor the new tires will have a different coefficient of friction and that would cause emergency breaking to be problematic.

You really don't know much about vehicles and tyres do you?

Chris I do know a lot about autos and rotating front to rear will allow you to use up all the tread that you paid for, have better balanced handling and breaking. As for your car something is wrong when 3 are worn enough to merit replacement and the 4th is OK. Even if you did replace the tires with the same make and model as the survivor the new tires will have a different coefficient of friction and that would cause emergency breaking to be problematic.

What Chris is saying is fine for a 1950 tire on a 1950 car. I suspect that is when he learned about tires and hasn't kept up to date.

One very important thing to realize is on a modern car the traction control system operates by counting rotation to determine angular velocity as does the anti-lock brakes. If you have tires with different diameters the system can get tricked into either not acting or acting when it shouldn't. Either can kill you. Many of those systems will also deactivate if they think the donut tire is on the car. That can be a surprise.

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3+1 setup that you are talking about is perfectly legal and acceptable. If it wasn't the tyre place would have informed me.

Well you explained the odd tire, the arrangement may be legal but certainly is not the most safe as I explained.
As an aside my Subaru mandates changing all 4 because of the all wheel drive. Even the smallest differences in circumference will mess up the center differential

Subaru would mandate changing all 4 because firstly, they cover themselves for legal action if someone had an accident from mis-matched tyres,

No mismatched tires would break the AWD center differential

secondly it gives their Main agents more profit

No one I know ever buys tires at a car dealer.

To cut a long story short...

The main aim of having transport is to use it & to do that, it has to be legally roadworthy & safe to use.

...how that is done is neither here nor there, as long as it is done.

Have you worked out the rolling diameter of a new tyre that in under inflated by say 5 psi,

As a point of order air pressure does not change the circumference of a tire.

As a point of order air pressure does not change the circumference of a tire.

Through the Chair, the circumference of a tyre has nothing to do with the rolling diameter.

Air pressure in the tyre has a massive efect on the contact patch , under inflated it makes the tyre spred out so a larger contact area but at the cost of more resistance to the road so wear / feul economy suffer . Just the same for a over inflated tyre but personaly i think it's a lot safer to be under than over .
I used to crew for my friend drag racing up santa pod for nearly 20 years and we ran the car with say 12 / 13 psi rears ( a lot less than road use )just so we got the traction off the " tree " and we ran slicks , on a fully preped track we took em down to 9 / 10 psi depending on the weather conditions /temp ( track glue on that strip could take your steelys off your feet and ain't joking !! )

As a point of order air pressure does not change the circumference of a tire.

Through the Chair, the circumference of a tyre has nothing to do with the rolling diameter.

C = 2 pi (d/2)^2

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know full well that the circumference of a circle is C

I always 4t "c " stood for the speed of light , know it does in 1 famous / infamous equation .

Those of us that went to school and were taught Euclidean geometry

Duno what it was called but i got taught Geometery at skool ( yea even in Suffolk that was ;-) ) , use " trig " for every job i take on , since i started working for meself ;-)

Is it just the internet round here or does seti main keep " dissapearing " then coming back this afternoon ??
Sometimes the site loads up like normal but a few times i get " connection problems can't reach seti " message
BT " infinity "Internet connection ( but not tv one ) here but no problems with other sites local news / BBC News , I player or kodi box work without any problems

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Just found out the problem here , BT are adding some new connections to the green box at the top of the estate for the new council orifices , strange how everything else seams ok just probs connecting to seti. Would of 4t it would cause problems on the whole cabbodle but what does i know bout BT ;-)

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Agree > Seems to be SETI related since before the outrage this week.
I have had intermittent issues connecting to the message board with random time outs, web site not available messages and a twice DNS lookup error messages.

As I said before "air pressure does not change the circumference of a tire" but it will affect the rolling diameter on the road, which in turn will affect tread wear.

??circumference and diameter not related?? Is your name tRump?

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I always thought C=Pi x diameter.

Up early as got an early appointment at Addenbrookes, so I'll stick my head out the window on the way down to check it :-)