I originally had 17" wheels on my car but I replaced with 18".
I still have the original space saver in the boot as a spare.
If I have a flat will I be able to use this to get me home?
On the car my tyres are 225/40/18
On the space saver I have 125/70/18
I presume the rolling diameter is out as it was meant to be used with 17" rims.