I also have found that foam tires will last alot longer if you have a smooth surface to run on. They also handle a lot better but as they wear down your frame gets closer to the ground.
If you choose to run rubber tires HPI makes a variety of tread patterns and go with the deepest treads so they last longer.
Foam tires are measured in the hardness of the foam and most manufactures use a Shore Rating. A 40 Shore tire will be harder than a 30 shore tire. So if you are running on a parking lot that is not very smooth go for the highest shore tire to increase the life of the tires. Some manufactures like Jaco also use a color scheme for the hardness of the tires.
They also measured in the width of the tire and on these cars the 26mm or 28mm tires will fit the best. 30mm tires might scrub unless there is a huge offset on the rim. Most rims come with 0 percent offset.
On my Mugen MTX-3 it will handle 30mm tires on the rear but only 26mm and 28mm tires on the front.
