wheels

[jmn_castro]

what's the diference between
205/60 15
215/50 16
225/40 17
do they all have the same rolling circumference?
factory is 205/60 15
any of the others will be ok?
thanks
mike

[dinsdale]

no, the last number ie, 15,16 and 17 refer to the inner wheel diameter so if you have 15 inch wheels then the 16 and 17 inch tyres will not fit the wheel, they would be ok if you were to buy new wheels however

[New Judge]

205/60 15 means as follows:

205 is the width (in millimetres) of the tread. 60 is the profile ratio of the tyre (i.e. its wall height is 60% of the tread width). 15 is its diameter in inches.

Only tyres of 15 inches diameter will fit a 15 inch rim. However you can vary the tread width and profile slightly.

A low profile tyre (one where the profile ratio is low) will have a smaller rolling circumference than a higher profile tyre. This is because although the rim diameter is the same the �height� of the tyre will be less. So the diameter of the tyre (and hence its circumference) will be less.

Ideally you should not depart from the factory fitted spec. However, consult a tyre dealer if you intend to do so.

[kempie]

205/60 15 - 1912 mm
215/50 16 - 1895 mm (speedo error = -0.55 mph)
225/40 17 - 1866 mm (speedo error = -1.50 mph)

http://www.club80-90syncro.co.uk/Syncro_websit e/TechnicalPages/TRC%20calculator.htm

[kempie]

^^^ Speedo error @ ~60 mph