Them Tyre sizes

[Anonymous]

Just been to Halfords about those tyres!
They have said that 195/45/15 will throw my speedo out! Will this be a major problem???

They said I needed 195/50/15

 

[Tom]

Yes it will, and yes you do.

 

[Anonymous]

Thanks Tom, is it a major problem though? I thought I read recently that it will put speedo out by 1mph??
Will it **** the car in any way??
Thanks

 

[Wimmy]

Wont knacker the car but will give u incorrect readings on your milometer and speedometer. Mine's out. Use the tyre/speed calculator on the bravo-guide to check how much it will be out.

I have 195/50/15's on mine which actually have a smaller diameter than the standard tyres on my model

 

[Anonymous]

Thanks Pal!!

 

[Anonymous]

ok, assuming you already had 175/65/14's on, then yeah you wanted 195/15/15

The size they recommended would still be out, but only by -1.2%

The size you have is actually -4.7% out. So your speedo will actually read 4.7% too fast.

This means that, when your speedo is saying you are doing 60MPH, you are actually only doing 57.3%. I wouldn't worry about it, but if you need to replace the tyres, you MUST replace them in pairs to change to the correct size.

Also, I am told it may afect your braking a little if you have the wrong tyres on...

 

[Anonymous]

Does that mean my milometer will add more miles on than I have really done?? So if a had done 57.3 miles it would actually put 60 miles onto the cars total mileage??

Thanks to you all for your helpful comments by the way!!

 

[Tom]

http://www.bravo-guide.co.uk/tyres.htm

It will put the speedo out by about 3 MPH.

 

[LightWarrior]

actually, that should say 57.3MPH, not %... And of course, for every 1000 miles you drive, your counter will add 1047... not a HUGE error mind you