Tire Ratios

My new Civic has 16" (205/55R/16) aluminum wheels so I think i'm going to
get some winter rims and tires for it for the comming winter.

I was wondering if I could use 15" wheels & tires instead? If so, what size
tire should I get to keep the right ratio? Anyone know how I can find out?
16 inch low profile winter tires, which would fit right, are just too
expensive really and there's no need for such tires for the winter.

 

You could get a 195/65-15 and your speedometer would be off by only 0.4%.

 

Try this:
http://www.eunos.com/tirecalc/

-Dave

 

Yes you can use 15" wheels and tires. This is a -1 fitment (minus one). The
goal is to get a wheel/tire combination that gives you the same height and
circumference. This is a lot more complicated than it should be because
different measurement systems are at work here... The 205 is in millimeters,
the 55 is in per cent and the 16 is in inches. What you do is go to a good
reputable tire shop and tell them what you want to do and let them do the
math for you - or - find the sidewall height expressed as a percentage of
the width (205 X .55 in your case), then multiply by two because you have a
sidewall at the top and bottom of the tire, then convert that result, which
is in millimeters, to inches. Simply multiply by 25.4. Add this result to 16
(the wheel diameter). This answer is the height of your tire. Now you select
a tire in 15 inch and match it, as closely as possible, to your stock
tire/wheel .... Just as a starting point, I would suggest about a 215/60/15.
Hope this helps.

DaveD

 

I would suggest 195/55/R15 for a civic