andylb Posted August 2, 2011 Posted August 2, 2011 Hi all, I was looking at new tyres, and noticed that in falken FK452s the 225 40 18 is over £30 cheaper each than the 225 45 18 at most suppliers. Obviously a £60 saving on a pair of tyres is desirable. Will there be any issues going 225 40 over 225 45?
Willy P Posted August 2, 2011 Posted August 2, 2011 This will change your rolling radius and play tricks on your traction control, causing it to kick in all the time I think mate, sorry. Always best to keep the same rolling radius...
andylb Posted August 2, 2011 Author Posted August 2, 2011 are we talking about front tyres Yes front tyres. Does the traction control monitor the front wheels? I wasn't sure how much a difference 5mm would make, didn't realise the traction control would be so sensitive. Do Zs with 17" wheels have the same rolling radius?
Beau Posted August 2, 2011 Posted August 2, 2011 are we talking about front tyres Yes front tyres. Does the traction control monitor the front wheels? I wasn't sure how much a difference 5mm would make, didn't realise the traction control would be so sensitive. Do Zs with 17" wheels have the same rolling radius? Yes, 17" willl have the same rolling diamter or close to the 18". It is best to keep it orignial or as close as possible. Or else there has been cases where the traction control kicks in at low speed when cornering ect. It can be quite dangerous.
RisingPower Posted August 2, 2011 Posted August 2, 2011 Makes 3.4% difference, i.e above what I believe is the recommended difference in rolling radius.
andylb Posted August 2, 2011 Author Posted August 2, 2011 Makes 3.4% difference, i.e above what I believe is the recommended difference in rolling radius. Isn't the difference between a brand new tyre, and a close to the limit tyre 7mm? Thus making an even greater difference in rolling radius over the life of a tyre than would be present with a smaller diameter. I understand of course that there is a potential for the smaller diameter tyre to be 5mm + 7mm different (from a brand new standard size tyre to a close to the limit smaller tyre)
Lincolnbaggie Posted August 3, 2011 Posted August 3, 2011 The 40 and 45 doesn't refer to mm; it is the % of the width (40% of 225 = 90mm, 45% of 225 = 101.25 mm, so a difference of 11.25 mm).
brillomaster Posted December 18, 2011 Posted December 18, 2011 holy thread resurrection batman! So what about if you swapped both fronts and rears to be 40 profile? obv. the rolling diameter would be way out, but if the relative difference between the front and rear wheels stayed the same would this still kick in the TCS? maybe go from 225 45 to 235 40 on the front, and from 245 45 to 255 40 on the rear?
Lexx Posted December 18, 2011 Posted December 18, 2011 viewtopic.php?f=60&t=56736 Exactly that is being discussed in above thread. I'm now looking this one to prevent too separate thread running.
Recommended Posts