difference between tires plz reply
#11
09-22-2006, 01:48 AM
RE: difference between tires plz reply
ORIGINAL: Turbo i3uddha
u sure? i thought the only thing taht affected speedo readout was actual
diameter + or - several inches...
I might be wrong though...
u sure? i thought the only thing taht affected speedo readout was actual
diameter + or - several inches...
I might be wrong though...
#12
09-22-2006, 02:28 AM
RE: difference between tires plz reply
ORIGINAL: chaos92287
some guy on a bimmer forum told me that so it may be wrong lol
some guy on a bimmer forum told me that so it may be wrong lol
HEhahahahha yeah.. no wonder..
Im sure that width (especially a matter of 10mm)
wont affect your speedo accuracy at alll...
#13
09-22-2006, 07:30 AM
RE: difference between tires plz reply
Second set of numbers is the sidewal height. Meaning that if you go higher in numbers the more sidewall you'll have. So 235/40/18 is the same height as a 225/40/18.
FYI, I believe you can recode your vehicle with VAGCOM to compensate for this discrepancy and adjust the instrument cluster for the tires you chose. Check the Ross Tech site for more info.
#16
09-22-2006, 03:07 PM
RE: difference between tires plz reply
The sidewall height is not the same, even on the same rims.
To clarify, 225/40 tires will have the same sidewall height regardless if they are for 17", 18", or any other size rims. This is because sidewall height is a function of the tire width multiplied by the ratio indicated by the second number. If neither of the first 2 numbers change, then the sidewall height remains unchanged.
However, 225/40, 235/40, 245/40, 255/40, will all have different sidewall heights when mounted on the same size rim for the same reason.
This explains, for example, why you must go to to a lower ratio when increasing the width significantly. Hope this helps.
To clarify, 225/40 tires will have the same sidewall height regardless if they are for 17", 18", or any other size rims. This is because sidewall height is a function of the tire width multiplied by the ratio indicated by the second number. If neither of the first 2 numbers change, then the sidewall height remains unchanged.
However, 225/40, 235/40, 245/40, 255/40, will all have different sidewall heights when mounted on the same size rim for the same reason.
This explains, for example, why you must go to to a lower ratio when increasing the width significantly. Hope this helps.
#17
09-22-2006, 04:01 PM
RE: difference between tires plz reply
Do some more homework on sidewall height. Not Aspect Ratio's.
Side wall height on a 225/40 is the same as a 235/40. Sidewall heigth. Period.
Aspect ratio is different because of the wider tire.
Here you go. Find out for yourself(notice sidwall height is the same if you have a 225/40/17 vs 235/40/18):
http://www.miata.net/garage/tirecalcold.html
Side wall height on a 225/40 is the same as a 235/40. Sidewall heigth. Period.
Aspect ratio is different because of the wider tire.
Here you go. Find out for yourself(notice sidwall height is the same if you have a 225/40/17 vs 235/40/18):
http://www.miata.net/garage/tirecalcold.html
#19
09-22-2006, 04:37 PM
RE: difference between tires plz reply
ughhhh.
Ok this is getting retarded. This is very very basic tire stuff.
Please follow the Wiki link below. Specifically the parts about tire geometry, tire codes, and look at the diagrams. I have quoted a small portion for you here. In short, Quaberto's and my original post are correct.
Wikipedia on Tire Codes
Ok this is getting retarded. This is very very basic tire stuff.
Please follow the Wiki link below. Specifically the parts about tire geometry, tire codes, and look at the diagrams. I have quoted a small portion for you here. In short, Quaberto's and my original post are correct.
Wikipedia on Tire Codes
Tire geometry
When referring to the purely geometrical data, a shortened form of the full notation is used. To take a common example, 195/55R16 would mean that the width of the tire is 195 mm at the widest point, the height of the side-wall of the tire is 55% of the width (107 mm in this example) and that the tire fits 16 inch diameter wheels.
Less commonly used in the USA and Europe (but often in Japan for example) is a notation that indicates the full tire diameter instead of the side-wall height. To take the same example, a 16 inch wheel would have a diameter of 406 mm. Adding twice the tire height (2x107 mm) makes a total 620 mm tire diameter. Hence, a 195/55R16 tire might alternatively be labelled 195/620R16.
Whilst this is theoretically ambiguous, in practice these two notations may easily be distinguished because the height of the side-wall of an automotive tire is typically much less than the width. Hence when the height is expressed a percentage of the width, it is almost always less than 100% (and certainly less than 200%). Conversely, vehicle tire diameters are always larger than 200 mm. Therefore, if the second number is more than 200, then it is almost certain the Japanese notation is being used - if it's less than 200 then the US/European notation is being used.
When referring to the purely geometrical data, a shortened form of the full notation is used. To take a common example, 195/55R16 would mean that the width of the tire is 195 mm at the widest point, the height of the side-wall of the tire is 55% of the width (107 mm in this example) and that the tire fits 16 inch diameter wheels.
Less commonly used in the USA and Europe (but often in Japan for example) is a notation that indicates the full tire diameter instead of the side-wall height. To take the same example, a 16 inch wheel would have a diameter of 406 mm. Adding twice the tire height (2x107 mm) makes a total 620 mm tire diameter. Hence, a 195/55R16 tire might alternatively be labelled 195/620R16.
Whilst this is theoretically ambiguous, in practice these two notations may easily be distinguished because the height of the side-wall of an automotive tire is typically much less than the width. Hence when the height is expressed a percentage of the width, it is almost always less than 100% (and certainly less than 200%). Conversely, vehicle tire diameters are always larger than 200 mm. Therefore, if the second number is more than 200, then it is almost certain the Japanese notation is being used - if it's less than 200 then the US/European notation is being used.