Spare wheel

[Travis]

Hi  Jazz ex tyre size 185/55/16 could i use a 185/60/15 for a spare with out any speed restrictions.
Many thanks

[Expatman]

No - the diameter and circumference of the 185/60/16 tyre is greater than that of the 185/55/16 tyre so the car will be unbalanced. Tyre pressure alarm will activate and handling will be compromised. If you do use the 185/60 as a spare I would drive carefully and moderately to a tyre depot for a repair.

[Travis]

Hi thanks for the reply but i made a mistake spare wheel size 185/60/15.
Thanks

[Expatman]

Well the diameter of the 185/55/16 is 610mm and diameter of the 185/60/15 is 603mm, circumference of 185/55/16 is 1916mm and of the other is 1894mm.
So, while not ideal, you could probably drive with the “spare” for some time. However, it is not ideal and difference in wall height would affect handling, also, if you had an accident while driving with mismatched tyres your insurance cover could be problematic. The tyre pressure alarm will certainly warn you that something is wrong - it uses relative circumference as a measure.

[Travis]

Thank you very much for the information, unable to get a 16 inch at the moment but will keep looking.
Many thanks again.

[Karoq]

Try this for 'size' (boom-boom!)
https://tiresize.com/comparison/