Tyre Wear in Centre
Discussion
I went to a pcgb meeting the other night where somebody gave a talk on wheel and tyre set up, they used a tyre that was worn in the middle as an example of what happens to a poorly inflated tyre. Unfortuantley the talk was boring me to tears so I cant remeber whether it was low inflated or high inflated tyres that cause this. What I do remember is that excessive speed does cause this type of wear in a tyre.
Hi 
Yes they are OVER inflated...
The way I set my pressures on my 18s on my 928 is as follows...
Get a thermal laser gun (little gun thing with red laser beam that reads temperature..around £30 off ebay)
Drive for a few miles fairly fast once tyres are up to normal temp...
Stop in layby....aim gun across tyre...read temps...they should be EVEN....if centre temp is higher than edges then LOWER pressure....etc etc...
Like this one but dont buy unless in UK !!
http://cgi.ebay.co.uk/CE-Certified-Gu
All the best Brett
Yes they are OVER inflated...
The way I set my pressures on my 18s on my 928 is as follows...
Get a thermal laser gun (little gun thing with red laser beam that reads temperature..around £30 off ebay)
Drive for a few miles fairly fast once tyres are up to normal temp...
Stop in layby....aim gun across tyre...read temps...they should be EVEN....if centre temp is higher than edges then LOWER pressure....etc etc...
Like this one but dont buy unless in UK !!
http://cgi.ebay.co.uk/CE-Certified-Gu
All the best Brett
Edited by Brett928S2 on Tuesday 13th March 11:35
I agree probably over-inflated.
An infrared thermometer isn't a very good way of measuring tyre temperatures, it only measures the surface temperature not the temperature inside the tread - which is a much better indicator of how hard the tyre is working. You really need a tyre pyrometer which will read the temperature within the tread.
You won't get even readings across the tyre, but what you should aim for is the middle being roughly the average of the inner and outer edges.
The actual temperature distribution will vary enormously depending on what sort of driving you do - hooning round roundabouts will cook the outer edges while they will be stone cold on a motorway. So taking snap measurements isn't a good way to manage long term average tyre wear. The best way to do that is simply to monitor how they are wearing.
An infrared thermometer isn't a very good way of measuring tyre temperatures, it only measures the surface temperature not the temperature inside the tread - which is a much better indicator of how hard the tyre is working. You really need a tyre pyrometer which will read the temperature within the tread.
You won't get even readings across the tyre, but what you should aim for is the middle being roughly the average of the inner and outer edges.
The actual temperature distribution will vary enormously depending on what sort of driving you do - hooning round roundabouts will cook the outer edges while they will be stone cold on a motorway. So taking snap measurements isn't a good way to manage long term average tyre wear. The best way to do that is simply to monitor how they are wearing.
GreenV8S said:
I agree probably over-inflated.
An infrared thermometer isn't a very good way of measuring tyre temperatures, it only measures the surface temperature not the temperature inside the tread - which is a much better indicator of how hard the tyre is working. You really need a tyre pyrometer which will read the temperature within the tread.
You won't get even readings across the tyre, but what you should aim for is the middle being roughly the average of the inner and outer edges.
The actual temperature distribution will vary enormously depending on what sort of driving you do - hooning round roundabouts will cook the outer edges while they will be stone cold on a motorway. So taking snap measurements isn't a good way to manage long term average tyre wear. The best way to do that is simply to monitor how they are wearing.
An infrared thermometer isn't a very good way of measuring tyre temperatures, it only measures the surface temperature not the temperature inside the tread - which is a much better indicator of how hard the tyre is working. You really need a tyre pyrometer which will read the temperature within the tread.
You won't get even readings across the tyre, but what you should aim for is the middle being roughly the average of the inner and outer edges.
The actual temperature distribution will vary enormously depending on what sort of driving you do - hooning round roundabouts will cook the outer edges while they will be stone cold on a motorway. So taking snap measurements isn't a good way to manage long term average tyre wear. The best way to do that is simply to monitor how they are wearing.
Hi
I agree with some of the above....but a couple of points....
Most of a tyres time is spent in straight lines..not going around corners so a temp reading done after straight running is on AVERAGE a better way to do it...
Monitoring a tyres wear by looking is a VERY expensive way to do it as you have probably lost half the tread by the time you notice the difference between the centre and the edges...
My way you can drop the pressure BEFORE you actually SEE the wear....
Higher temp in middle = over inflated
Lower temp in middle = under inflated
One other advantage of an infrared temp gun is that it works even if you change make of tyre (as tyre compounds are different you cannot assume all tyres of the same size will run properly at the same pressure)
p.s.. When I said make sure you buy from a UK supplier...I meant NOT from someone selling on Ebay from Taiwan or Hongkong !!
Also do not buy the Snap-On version unless cheap (they usually go for silly money)
All the best Brett
I had a query when I was buying new tyres recently, I wanted to know what the 'n' rating was about. As usual, when I want to know something, I just went straight to Porsche HQ. They patched me through to the branch in Chester where their 'best tyre man' works. He was really helpful, explaining what the 'n' rating was about, and finishing with, quote - "By the way, the book says the tyre pressures should be 36psi, which is fine for the German snooker table roads, however for British roads we recommend our customers to run the tyres 2 -3 psi lower, which will give you a better ride and make your tyres last longer".
Hope that's useful to you.
Hope that's useful to you.
john ward said:
I had a query when I was buying new tyres recently, I wanted to know what the 'n' rating was about. As usual, when I want to know something, I just went straight to Porsche HQ. They patched me through to the branch in Chester where their 'best tyre man' works. He was really helpful, explaining what the 'n' rating was about, and finishing with, quote - "By the way, the book says the tyre pressures should be 36psi, which is fine for the German snooker table roads, however for British roads we recommend our customers to run the tyres 2 -3 psi lower, which will give you a better ride and make your tyres last longer".
Hope that's useful to you.
Hope that's useful to you.
Front and rear?
Book says 29 front and 36 rear.
Brett928S2 said:
Hi
Yes they are OVER inflated...
The way I set my pressures on my 18s on my 928 is as follows...
Get a thermal laser gun (little gun thing with red laser beam that reads temperature..around £30 off ebay)
Drive for a few miles fairly fast once tyres are up to normal temp...
Stop in layby....aim gun across tyre...read temps...they should be EVEN....if centre temp is higher than edges then LOWER pressure....etc etc...
Like this one but dont buy unless in UK !!
http://cgi.ebay.co.uk/CE-Certified-Gu
All the best Brett
Yes they are OVER inflated...
The way I set my pressures on my 18s on my 928 is as follows...
Get a thermal laser gun (little gun thing with red laser beam that reads temperature..around £30 off ebay)
Drive for a few miles fairly fast once tyres are up to normal temp...
Stop in layby....aim gun across tyre...read temps...they should be EVEN....if centre temp is higher than edges then LOWER pressure....etc etc...
Like this one but dont buy unless in UK !!
http://cgi.ebay.co.uk/CE-Certified-Gu
All the best Brett
Edited by Brett928S2 on Tuesday 13th March 11:35
flaming hell. I knew that the 928 was luxuriously kitted out, but your own personal laser gun???
Hi
Lollll.....928s have everything...lol
Actually the temp gun is extremely useful , you can for instance point it at the base of a spark plug and the temp will tell you if its missfiring etc etc...also useful for me with my nitrous...to see if my bottle heater blanket is in correct place to give even temperature across whole bottle....you can even use it for your kids ..point at forehead...see if they are ill
All the best Brett
Lollll.....928s have everything...lol
Actually the temp gun is extremely useful , you can for instance point it at the base of a spark plug and the temp will tell you if its missfiring etc etc...also useful for me with my nitrous...to see if my bottle heater blanket is in correct place to give even temperature across whole bottle....you can even use it for your kids ..point at forehead...see if they are ill
All the best Brett
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