Wheel / Tire 101 question

[PHJ426]

Looking at doing the G machine deal to a 72 Road Runner.

Is there a calculator that converts the metric tire size and displays the tires dimensions in inches?

Never ran a tire of these dimensions on an older car before is there a place I can read up on the comparison of 17 / 18 inch wheel and tire combos compared to eachother?

Not sure what tire diameter I want to run with the car set up like this.

Edit I found this site that converts metric to inch dimensions for tires:
http://www.dakota-truck.net/TIRECALC/tirecalc.html

[AllSpeedAndy]

Most tire manufactors have a demention break down of each tire size they offer right on there web site as well.

[wiedemab]

Example:

245/45R17

245 - section width
convert to inches by dividing by 25.4mm per inch = 9.65in

45 - aspect ratio
take .45 X 9.65in = 4.34in this is the sidewall height from the rim mount surface
double it to get 8.68in

17 - rim diameter at tire mounting surface

Add the 8.68in to 17in and get 25.68in tall.

This will get you very close. You are obviously going to have some deflection in the tire from the weight of the vehicle, but it will be very close.

[DriverzInc]

Well explained by the above post. Here is a photo of my 69 Roadrunner on 17's, and a the rendering of the 19/20 combo I plan on running.

Have you made a decision on wheel style yet?

http://i37.photobucket.com/albums/e99/Hensons/69Runner_AmericanRacingWheels015.jpg
http://i37.photobucket.com/albums/e99/Hensons/RoadRunner_FinalRendering.jpg

[BonzoHansen]

http://www.1010tires.com/newforum/default.aspx

[PHJ426]

Hey Jon,

What size wheels and tires are on the Road Runner?

I have just started looking into the build so its all in the planning stages right now. Going to put the 72 on a Chassis stiffening plan with the subframe connectors etc etc.

The rear springs will be moving inboard also so I would like to get that mocked up and see how much room I will have.

I was thinking 245/45R17 front and 295/45R18 out back. How do you like the selection of wheels and tires in that spec? Any other suggestions for sizes?

Need to clear the 13" rotors with Viper calipers on front and SVO discs out back also.

Looking for the Muscle car look still with the handeling so that kinda tells you the direction I would like to go. I dont care for a ralley or magnum look a like wheel in a larger diameter.

Thanks for the input