A friend of mine has a W-reg Toyota MR2 which she purchased from new (has covered approx. 15,000 miles). She has noticed that both the front tyres (Bridgestone I think) are wearing in a strange manner. The tread blocks on the outer and inner edge are approximately 2-3 mm lower than the adjacent central blocks.
She took the car to her local garage (independent) and he said that she should take the car to the Toyota dealership because, in his experience, he had not encountered this type of problem before (he said it was not the tracking).
She then took the car to the Toyota dealership and they performed a 4-wheel alignment test and discovered that the front wheels were out of alignment.
However, although the dealership have done this, she is still worried that there may still be an underlying problem because of the nature of the wear on the tyres.
I always believed that if your front wheels were out of alignment you would experience a feathered edge when rubbing your hands across the tread and that the wear on the tread blocks would be gradual, whereas in this case it's only the outer and inner blocks that are distinctively lower.
I would be grateful if anybody had any ideas regarding this problem.
Many thanks,
Jason
P.S. The front tyre pressures when checked after the visit to Toyota were approx. 2psi over on one side and 5psi over on the other.
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Jason.
Many of the cars I look after suffer a similar problem to a greater or lesser extent. With the high performance and grip available from most modern cars, particularly as they are likely to be FWD with PAS. tyres are under great stress.
Yet people just do not check them often enough, weekly is the requirement but I know some folks never check them between services. Two of the cars I have in at six monthly intervals usually have one or more tyres at about 10-12psi. I note this for the customer and they usually admit "you were the last person to check them at the previous service, they looked OK".
Under-inflation will cause this wear on both outer edges and some makes of tyres do seem to wear as if the outer blocks were somehow separate to the rest.
Even pressures 5psi down from normal over time will cause this. And let's be realistic....even the more careful may only get round to checking pressures monthly. In this time a tyre may have dropped from the set 32psi to about 24psi. On average the tyre is running constantly low and this will show up in the outer edge wear pattern, particularly in the second half of the tyre's life.
Also consider the "Milton Keynes Syndrom" where cars driven on such road systems suffer nearside front tyre outer shoulder wear. All due to the frequent roundabouts.
David
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I would be worried if my tyres dropped 8 psi in a month. Normally the drop I find is on average about 0.5psi. However changes in the air temperature can alter this temporarily.
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Fair point Andrew, I was talking about a worse case situation. That high loss tends to happen to a couple of the vehicles I see, one a Discovery with alloys and the other a Granada with alloys. Neither has a puncture or valve problem and all wheels are affected.
But the point I'm making really is that, in general, most people tend to leave checking the pressures too long and the average pressure ends up being low and causing edge wear.
David
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If you can measure the pressure drop accurately on your tyres by 0.5psi then you must work for an F1 team. Come on - be serious!?
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I have an MR2 but I have only covered around 2.5k miles - no signs of wear yet. I am wary of tyre wear though having owned an MGF before.
I ran the MGF from new and suffered rapid uneven tyre wear usually on the inside of the fronts. At first I thought it was down to the tracking. But, despite 4 wheel laser alignment the problem returned £5k miles later. I never did get the problem completely solved even after 3 years and 40k miles. Tyre pressures were regularly checked. I guess it was a combination of the poor quality suspension set up.
I doubt this is the case with the MR2 though. Get your dealer to check the tracking.
On the subject of tyre pressures I find 'garages' in general don't care about pressure. They always over inflate. I check them on return and correct them before driving.
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Us garages have to have our tyre pressure equipment calibrated and certificated every six months - the guages you and your local garage forecourt posses don't and have been proved in many cases to be wholly inaccurate. Please give us some credit - we're not all cowboys who don't care!
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