245/45/17 are stock size for a load of different Mustangs so they tend to be easy to find and cheaper than similar sizes. I run them on my Malibu 4dr. Right now I have Federal super steel 595 on the rear and they suck. It tracks all over and tread life is low. Had some falken ze950 that wouldn't tolerate the cars power even when new. Became straight scary at half tread life, would spin wildly at half throttle, like driving on ice. They are on the front now and I don't care for them there either. Had some sentury uhp cheapies that were quite good. Car tracked nice, was predictable, and would actually hook and go above half tread life. I would definitely run them again.