The difference between 14- and 15-inch wheel rims may seem to be only an inch of variance in diameter, but this difference can have an impact on the overall performance of the vehicle. The rim size determines the size of tires that can be used on the vehicle and how that vehicle performs based upon rim-related factors including height and handling.
A larger rim and thus larger tire can enhance the profile of a vehicle, lifting it further from the ground. This can affect traction and sightlines. A smaller rim with a smaller tire can lead to a smoother ride with the vehicle hugging closer to the road.
When choosing a different sized rim and tire for a vehicle, consider the type of car or truck, the original size of the wheel rims and the expected performance. When a large increase or decrease is desired, additional modifications may need to be considered in order for the vehicle to accommodate being that much higher or lower to the ground. Most commonly, this is seen when a vehicle is "lifted" or its suspension is raised in order to fit it with tires much larger than originally used.