Everything folks have said about the advantages of narrower vs. wider tires is true. However, no one has said anything about the advantages of wider over narrower tires. That fat contact patch may slow you down--but it will help you avoid what really slows you down, namely sliding out and kissing the asphalt. And since I switched from 25s to 35s my rims have quit getting tweaked, I never get a snakebite flat going over railroad tracks at 20mph, and I can forget to pump up the tires for a week or two without the tires getting squirrely & flat-prone.

In other words, nothing's free. Narrow tires are better than wide tires--and vice versa. Before you swap, consider both the pluses & minuses. And remember--we males have trouble thinking when testosterone poisoning sets in...