Here's why:
* Original Wheel Size: 1962 Impalas used much smaller diameter wheels, typically in the 14-inch range. A jump to 20 inches is a massive increase.
* Backspacing and Offset: The distance from the mounting surface of the wheel to its inner edge (backspacing) and the offset (how far the mounting surface is from the center line of the wheel) are crucial for proper fitment. 20-inch wheels designed for modern cars will almost certainly have different backspacing and offset than what's needed for a '62 Impala. Incorrect values can cause rubbing on the suspension components, body, or brakes.
* Brake Clearance: 20-inch wheels often require larger brake calipers than those found on a classic Impala. You'd likely need to upgrade your entire braking system, a complex and potentially expensive undertaking.
* Suspension Geometry: The geometry of a '62 Impala's suspension wasn't designed for the weight and size of a 20-inch wheel and tire combination. This can affect handling and potentially damage suspension components.
* Overall Appearance: While some people like the "modern" look on a classic car, a 20-inch wheel on a '62 Impala would likely look disproportionate and out of place.
In short, while *technically* you might be able to *force* a 20-inch wheel onto a '62 Impala, it would require extensive modifications, potentially including custom suspension, brakes, and possibly even bodywork. The result might not be safe, reliable, or aesthetically pleasing. Sticking with wheels closer to the original size is strongly recommended.
