14 vs 15 inch tires

[thebarber]

Originally Posted by sbergman27

175mm * 0.65 = 113.75mm, unless I'm missing something.

nope, you're right....must have typed it wrong this morning

still, the bulk of the difference is not in the sidewall of the tire

[sbergman27]

Originally Posted by thebarber

still, the bulk of the difference is not in the sidewall of the tire

The taller sidewall offsets the smaller wheel size by 20%. But my point is really that, overall, there is not much difference between the two configurations. The 15 is 3.4% higher diameter. The 14 is 4.9% narrower.

[thebarber]

Originally Posted by sbergman27

The taller sidewall offsets the smaller wheel size by 20%. But my point is really that, overall, there is not much difference between the two configurations. The 15 is 3.4% higher diameter. The 14 is 4.9% narrower.

1010tires.com suggests no more than 3% difference when buying new tires

that said, i ran 205-55-15 all last summer vs my 175-65-14 stock stuff and i personally think the speedometer was more accurate.

@ 120kph, 3.4% can be the difference between getting pulled over or not getting pulled over...