The time has come to put this ride on the ground. That means wheels and tires and that means decisions on styles and sizes. Have you seen the selections available? I have. If it is round, someone has designed it into a wheel and wrapped some rubber around it.

In the end I decided to stay with the old school look that has been prevalent throughout this build and went with American Racing Wheels, Torq Thrust D style wheels. These are fifteen-inch wheels that are seven inches wide with gray painted spokes and a brushed aluminum rim.

How did I settle on fifteen inch wheels that are seven inches wide? Fifteen inch diameter wheels are the most common sized wheels out there and since the theme of this car has been and still is old school the choice came naturally. To determine the correct width all I had to do was to figure out the needed tire clearance and the wheel offset and that left me with the correct wheel width.

Okay, there is a little more to it than that. The first step to determining wheel width is to determine the tire clearance. If you mount a fat radial tire on a seven inch wide wheel you automatically have a total tire width of about nine inches. I have eleven inches of rear wheel well space as measured from the inside edge of the rear fender to the inside of the wheel well. Subtract nine inches of tire width from the eleven inches of wheel well space and I end up with about an inch of clearance on the inside and an inch of clearance on the outside. Thus the need for seven inch wide wheels.

That’s the easy part . The hard p art st art s when you pick up the phone to call the wheel guy an d h e asks about the desired wheel offset. What’s wheel offset?

Off set is defined as the distance from the edge of the back of the wheel to the mounting flange. In conjunction with off set you will also hear the term “back spacing”. These are two different measurements but result in the same outcome as far as wheel widths are concerned.

Here is how it works. If a seven inch wide wheel has a back spacing of 3.5-inches (the distance from the mounting flange to the inside edge of the wheel) it also has an off set of zero. That means the mounting flange is centered in the wheel (7 - 3.5 = 3.5). If a seven inch wide wheel has a back spacing of 2.5-inches it also has an off set of negative 1.0-inches. (7- (2.5+1.0) = 3.5) Negative off set simply means the mounting flange has been moved inboard, or closer to the inside edge of the wheel. A good example would be a seven inch wide “deep dish” wheel. This wheel coul d h ave an offset of up to negative five inches. Positive off set would be more like a wheel you see on newer vehicles where the wheel looks basically flat. The mounting flange is located near the outside edge of the wheel.

To determine what off set will work best I st art by laying a straight edge vertically on the axle mounting flange then measure the distance from the mounting flange to the inside edge of the fender wheel opening. That measurement is six inches.

Knowing that a seven inch wide wheel with a zero off set has a measurement of 3.5 inches from the mounting flange to the outside edge of the wheel, plus roughly one more inch taking into consideration the width of the mounted tire, and that leaves me with roughly one and a half inches of clearance between the tire and the fender. That’s not bad, but if you take a closer look at the pic you can see I’ve added a half inch wheel spacer to the axle for the purpose of doing some comparison work to see if adding more off set to the wheel would improve on the look. In the end I elected to go with seven inch wide wheels with a zero off set an d h ung the wheel spacer back on the wall.

You should also notice that I used the rear wheel well to make all of my calculations. Front wheel wells are always deeper and roomier to provide the needed clearance for turning and therefore don’t lend themselves well to calculating wheel sizes and off sets. You should, however, test fit the wheel of choice on the front just to be sure no clearance problems exist.

As for tires I’ll be going with BF Goodrich Radial T/A P215/65R 15 tires on the front and BF Goodrich Radial T /A P225/70 R15 tires on the rear. How does the car look with this combination? Nice!