Bigger Wheels-Changed Speedo Readings

[Ampstar]

Just replaced the standard 13-inch wheels on my ’94 car with 15 inch Turbine’s. The looks have improved immensely.
Didn’t realise how much bigger they would be over the 13’s (when I replaced the 15’s on my Saab with 17’s, the diameter stayed the same), but they do not appear to rub or touch anywhere.

My main concern is that the speedometer will now under read-can I get it recalibrated, or will I have to put marks on the speedo face for the “new” 30, 50 and 70 readings?

 

[CocoPops]

what tyres were used before and after?

 

[Ampstar]

Old wheels & tyres were 155/80/13.

New wheels & tyres 185/55/15. They fit fine, with no clearance probelms, even with hard cornering-feels much more sure footed now. But how far out will the speedo/odometer be now? Any way to calculate the difference (and maths is not my strong point!).

 

[Djw John]

Your speedo is reading 1.1% too slow so when your speedo shows 60 you are travelling at 60.7mph. No difference at all really

 

[Turkish]

i would have fitted 195/45/15s personally

 

[Djw John]

or when the wear out you can get 195/50s for cheaper