I think some of you mix up speed and acceleration. Traction: wider tires add to resistance and max straight line speed is achieved with the narrower tire. Gearing: as long as one gear is optimized for top speed, all other gears only serve acceleration. In the end weight reduction serves what purpose? If you wanted to safe fuel, buy the SRT ... or some Hybrid. If you wanted to race, by a race car. Enjoy having a monster and a big dinner - who cares that you had a 10 oz steak with a loaded potato, or do you eat salad to cut your times for a possible race at a possible red light meeting with a wannabe? By the way, reducing tire pressure will slow you down! As long as you have no spinning wheels, you want to reduce, not increase work the tire absorbs! A low pressure tire is deformed and power goes into continuous deformation. With much higher pressures the tire stays round and possibly less tire touches the road (again not to the point of spinning), resulting in - theoretically - better acceleration and top speed. As I said before, a tenth here or there, who cares? I drive high tire pressures for tire durability and without the spare as I keep tools and stuff down there. Certainly not to be “faster” 🙂