It's nothing new to upgrade to a more substantial wheel and tire combination on any car-especially a daily-driven vintage Mustang. Even so, we wanted to clearly illustrate the dramatic difference a more beefy wheel-and-tire combo makes on a car such as this '65 fastback.
As far as looks go, take a look at the photos and see for yourself. We'll admit a restored show car has a certain cool look to it with bias-ply redline tires and small 14-inch styled-steel wheels or wheel covers. But we feel that when a car, such as our '65, doesn't fall under the watchful eye of a show judge, it looks 10 times better with the larger wheels and tires. Leave the skinny tires for the show.
When we bought this car it had the 14x5-inch styled-steel wheels you see here and whitewall tires. Frankly, it was just a Band-Aid to fit only slightly larger BFGoodrich (great tires, yes, but just not big enough for our tastes) 185/60R4 radial T/As on the pizza-cutter-sized wheels.
For the past several years a number of companies have offered larger 15x7-inch steel wheels in a number of styles for '64 1/2-'66 Mustangs. A few years back we had a '66 fastback with 15x7-inch styled-steel wheels that rode on 225/50HR15 BFGoodrich Euro T/A skins. The car looked awesome, and when we sold it, we missed its hunkered-down road-racer look.
We wanted to bring back the look, but with a 15x7-inch Magnum 500 wheel such as was used on '66 Hertz Shelbys and '69-'70 Boss 302s. Made by Specialty Wheels, Magnum 500 wheels are available from California Mustang, and like the styled-steel wheels on the '66 they are a perfect fit on this '65. As with the '66, we went with the same size tire, but a much more sticky BFG Comp T/A ZR in a 225/50ZR15.
There's more. Not only does the car look better, it performs dramatically better, too, as demonstrated by the handling and braking tests we performed (see sidebar). In a 600-foot slalom, we picked a whopping six-plus mph in slalom speed! And this from a Mustang with stock suspension. All the details are explained below.
 First, we take our 15x7-inch...  First, we take our 15x7-inch Magnum 500 wheels and 225/50ZR15 BFGoodrich Comp T/A skins to a local tire shop to have them mounted... | 
...and spin balanced. |  Once mounted and balanced,...  Once mounted and balanced, the Magnum 500 center caps snap right onto the wheels. |