Leon MK3.5 space saver wheel question

[stepp]

Guys

I have searched....my leon has 18" wheels, i can get hold of space saver really cheap, its 18" but it measures 2cm bigger than my wheels/tyres.

Is this OK to use? i can see you can go slightly smaller but can't find anything saying you can go slightly bigger.

Bit of a noob when it comes to tyres size !

Thanks

 

[Glosphil]

What size tyre is on the space-saver wheel?

 

[stepp]

What size tyre is on the space-saver wheel?

It's 125 70 18

 

[bahyr]

Bigger than yours?

 

[stepp]

My tyres are 18" 225 40 18

Thats why its slightly bigger then 40 v 70............anyone know if its still OK to use it ?

 

[CupraGeezer]

Something is strange there. Your tyres should have a 90 mm (225 x 40%) sidewall while the spacesaver should have a 87.5 mm (125 mm x 70%) sidewall (wheel size is the same).

I know the calculated sidewall heights are theoretical and there are differences between tyre brands but a difference of 12.5 mm sounds like a lot (I'm assuming that your measurement is diametral rather than circumferential).

How did you measure your tyres? Did you do it without weight on the tyre?

 

[Glosphil]

A 225/40-18 has an overall diameter of 25.09 inches. A 185.70-18 space saver is 24.89 inches, so less than 1% difference. Fine as a spare.
The space saver should be fitted as a rear wheel and speed then limited to 50mph.

 

[SteveGSXR600K1]

Your tyre sizes are correct with 225 40 18 on the car and 125 70 18 on the spacesaver.

These are the sizes I have on my Leon.

 

[stepp]

Cheers guys, thanks for the help