changing tyre size

[qwerty247]

Does anyway know if its ok to change the tyre sizes?

I currently have 225/15/16 rear and 205/55/16 front.
would there be any problems if i changed the front to 205/60/15 ?
would it make the front higher or cause any driving problems?

thanks for any advise!

 

[BlackC55]

If your cars has ESP it will cause problems if your rolling radius of your tyres front to rear are very different. The ESP will "think" that your rear wheels will be spinning at a different speed than the front and it will cause the yellow triange to flash and restrict your speed. What car is it?

 

[BlackC55]

Also........It may mess with your suspension geometry and cause premeture tyre wear, poor handling and look cr4p.

 

[qwerty247]

by the sounds of it not a good idea then.
didnt realise it will affect the esp etc...
thanks for the info.

 

[BlackC55]

What car is it?

 

[Bobby Dazzler]

Going from 205/55 R16 to 205/60 R15 is likely to be OK as the difference in rolling radius and circumference is relatively small:

Rolling Radius: current 315.95mm versus new 313.50mm, ie -2.45mm difference
Circumference: current 1985.17mm versus new 1969.78mm, ie -15.39mm (-0.78%) difference.

Based on that I would say it's unlikely to cause steering, suspension, speedo/odo, systems problems.

I would suggest that you consult your MB dealer or tyre supplier for expert advice to be sure though.

I personally like to keep the dimensions exactly as the factory intended.

If you want to read up more on tyres, this is an excellent place to start: http://www.carbibles.com/tyre_bible.html

 

[qwerty247]

c class

 

[Bobby Dazzler]

Would you mind me asking which year? Do you know if you have ESP fitted?

 

[qwerty247]

sorry it was supposed to be changing to 205/60/16 (not 15)
thanks

 

[qwerty247]

thanks for the interesting link.
yes it has esp and its a 99

 

[Bobby Dazzler]

Going from 205/55 R16 to 205/60 R16 is probably pushing it a little as the difference in rolling radius is more significant:

Rolling Radius: current 315.95mm versus new 326.20mm, ie +10.25mm difference
Circumference: current 1985.17mm versus new 2049.57mm, ie +64.40mm (+3.24%) difference.

That would mean when your speedo reads 70mph you'd actually be travelling at 72.27 mph.

I would suggest that you consult your MB dealer or tyre supplier for expert advice to be sure.

What's the reason you're thinking of using a different size?

 

[Rory]

There's a tyre size calculator here:
http://www.miata.net/garage/tirecalc.html

 

[qwerty247]

always hit the wheel when parking so thought if the tyre is 'higher' then it would miss the pavement, hence the change to 60 rather than 55.

but after seeing all this info its probably not a good idea and just try to be better at parking...

thanks again

 

[dougal74]

always hit the wheel when parking so thought if the tyre is 'higher' then it would miss the pavement, hence the change to 60 rather than 55.

but after seeing all this info its probably not a good idea and just try to be better at parking...

thanks again

You are going the wrong way if you want to lessen kerb rash. It isn't the height it is the "bulge" created by the ratio of width to height in this case 55 or 60 AND the width of the tyre relative to the width of the rim.

The wider rear tyres 225 versus 205 would better protect your rims if matched at the front but might affect steering "feel". It would also eliminate any ESP problems.

You don't mention if you alloys are wider rear than front though, I am assuming they are not since they are 16"s.