Jon

Thinking about putting 205/55x15" Pirelli snows on my A4 to replace 195/65's. I know the diameter will be somewhat smaller, throwing the speedometer off some, and ground clearance reduced a little. Any other reasons not to do this?

Jon
96 A4/2.8 QM

Chris L.

I am not an expert on plus/minus sizing but this seems way off. By my calculations, you'll be affecting the sidewall height by more than 10% which, as you state, will affect ride height and speedo. But it will also affect odometer (yor mileage will read higher than actual miles driven which will affect your resale value) and I am sure that there are some onboard electronics that use speed readings to determine performance (ABS, traction control, Auto tranny, others?).

205/60-15 or 225/55-15 seem to be closer fits OR do a true plus-one and move to a 16" wheel with 205/55 - but I would call the Tirerack and speak to them since they ARE the experts.

Chris

PhilH

The difference between the stock size and the 205/55 15 is 4.4%. I've heard that you should stay within 3% although some say as much as 5% is ok. Either way, you'd be pushing the limits by trying this size.

I would think the change in gearing would be the biggest problem. Your engine would have to spin faster to maintain the same speed.<ul><li><a href="http://www.powerdog.com/tiresize.cgi">Tire size link</a></li></ul>

DMoore

By and large, the reason to go to a snow tire is to maximize performance in snow. A narrower, higher profile tire simply works better in those conditions. A 205 won't give as good traction in snow, and the improvement on a dry road will probably be pretty marginal due to tread squirm.

If you're trying to minimize dry road handling loss, and are willing to sacrifice performance in snow, an all season tire in a 195 might be a better trade off.

DMoore
'98 A42.8Qtip (with 195/65-15 Hakka's for winter)
'00 S4M (soon)

DL

You will want 205/60x15 not 205/55x15