I tried using the formula on CamaroZ28.com, but who ever did the HTML for it, put too many parenthesis in it. It's very confusing. . .atleast to me it is.

I have 245/50-16's on my car. Help me please. I'm trying to figure out what my RPM's should be at a given speed; 80 MPH for those of you that care.

 

25.7 or 26

 

First find out what your tire size is telling you.

245/50/16 means this:
The width of the tire is 245 millimeters.

The tire hiegth is 50 percent of the width.

Therefore 50 percent of 245mm or 122.5mm.

Your rim diameter is ofcourse 16 inches.
Coneversion factor needed for mm to inches is 0.0394 mm per linear inch.

If the radius of your rim is 8 inches and the radius of your tire(found by tire hieght) is 122.5mm or 4.8265 inches, then diameter is 2(r) or
2(8 + 4.82).

This should give you a tire hieght of 25.63 inches.

Hope this helps....

 

245/50/16

This is the easiest way:

245 * 50 / 2540 = 4.82 (Height of one sidewall)

4.82 * 2 = 9.65 (2 sidewalls, top and bottom)

9.65 + 16 = 25.65 (16 inches for the rim)


25.65 is the height of the tire.

Dividing in the beginning by 2540 converts from metric to standard.

 

Omar, i did the same formula with my 275/40/17 tire and go the same final answer as the 16" tire. Just posting to let others know that those 2 wheel and tire combos have the same tire height.