Comparing the wheels and tires of the base (14) and sport(15).. are they the same diameter overall or is the sport actually 1 inch larger? does this affect the mileage reading if so?

I'm under the impression that for mileage accuracy they would be fairly close (14 + regular tire or 15 + lower profile tire?) or am I way off here and 1 inch doesn't really make a difference?

Also does anyone know the combined weight of the 14 inch rims and tires of the base model?

 

The size does reflect the diameter of the wheel, so the 15's are an inch larger than the 14's. I don't know off hand if this is the case with the Fit, but often larger wheels are also wider than smaller options, which accomodates wider tires with shorter sidewalls. This, of course, is beneficial to handling.

It's my understanding that the speedo is set to reflect the wheel size. I'm sure people won't hesitate to correct me in the event that I'm mistaken

 

The rim is one inch larger, but the tire is (almost) half an inch shallower, so the overall size is closer:

• Base tires are 175/65R14: radius is (14in/2)+(175mm×65%) = 291.55mm
• Sport tires are 195/55R15: radius is (15in/2)+(195mm×55%) = 297.75mm
• Difference: 2.1%

Some people's odometers are off by that much anyway -- search for the (many) odometer threads. If you really want to know your own odometer accuracy, borrow a GPS.

 

How does one tell the odometer which size tires you have? I wouldn't have given this a second thought until I was driving to another town and ran across those distance markers I normally ignore.. in 10 kilometers it read 10.2 kilometers.. which is about 2%.. I have the LX model with 14 inch.. coincidence?

 

As far as anyone knows, you don't.
I originally thought the same, but some people with the sport model have reported similar numbers. In the US, there was a class-action lawsuit related to short-changing odometers; there are threads here about it.

(On my LX, with the stock wheels, my odometer was 1.5% short. Now I have 185/60R15 (r=301.5mm) and it's 1.3% long.)

 

The 14" steel wheel, stock hub cap and brand new tire of stock size weighs 36 pounds. For a reference, my PIAA sport mesh 17's and Hankook 205-40-17's weigh 3.5 pounds less.