"How do you feel the 1.5-2% reduction in weight?"
I can feel the difference in how the car handles. As I said in the previous post, put a 50 lb bag of dog food in the front boot and see how the car feels when cornering agressively. I am not sure what the total weight savings is that I am running these days, something like:
20 lbs cat-back exhaust system
15 lbs lightweight flywheel
25 lbs battery
30 lbs spare tire
Thats about 90 lbs which is over a 3% weight reduction for my base boxster. Especially in the 2.5 and 2.7L cars, I suspect most folks would find a reduction in weight of that sort translates into improved performance when driving in a spirited fashion. I know my car feels noticably less responsive with a passenger in the car with me. Now, if I could only spring for some lightweight seats, I could save another 40 lbs or so.....
Ed