0-60 and 1/4 mile are not good tests to see if there is something actually wrong with your car. If you think you have the flu, do you go for a jog and determine you are sick because it takes longer?

1) Did you change anything recently? If so, check that. Like did you change wheels or tires (and pressure), an exhaust, an intake, oil, spark plugs, etc?
2) If you didn't change anything and you're sure it's not just you getting used to the car, do a compression test.
3) If you can't find anything wrong yourself, take it to a mechanic.

 

its probably just in your head

 

Check your intake air filter. Mine was completely clogged after just 8,000 miles. There was house insulation and bird feathers and leaves and crap in the airbox.

 

because it's n/a.

 

i guess ill try recleaning the filter..

but thanks guys, it happened gradually, and last time i took it to a mechanic they said everything seemed fine

 

Did you switch gas brands recently? My S doesn't run as well when I use Mobil gas but when I switch to Chevron it seems to wake up a bit. That's the opinion of my butt dyno anyway, YMMV.

 

MAP sensor could be the culprit.

Get some mass airflow cleaner, take your map off, spray into map sense (not the connection). Let sit for 1 min, repeat 2 more times, but final time let sit for 5 minutes, shake any remaining cleaner out and sit for another 5 minutes (depending on temperature to allow drying).

The moment I did that I honestly felt like I was driving a new car.

 

I think it's just all in your head, or it's time for a tune up.

Sometimes this happens to me. I'll think the car is slower because i'm just use to it now.

The only time i can tell the car is slower and not my brain playing tricks on me, is when my MAP acts up. But that just makes the car hesitate on take off.

I'd check out your MAP, check those plugs, oil change and run some injector cleaner.

 

what kind of maintenance have you done to it? . Given your mileage it might benefit from some maintenance upgrades. I just got through replacing and cleaning a bunch of parts over winter, and I was just thinking to myself how great it was driving today. My car had 55k miles on it, 2002 MY ap1, performance seems to have improved quite a bit.

I replaced the plugs (gaps opened up pretty big on factory plugs). I changed the primary o2 sensor as the car seemed to be running rich. Cleaned the MAP, IAC, and throttle body. Swapped in some ap2 coilpacks, and sent my fuel injectors out for cleaning. New fluids in the engine, tranny, and diff. New pcv valve, and adjusted the valve clearances. New serpentine belt.

Your car might need some of these items.

 

well i think you develop a tolerance for speed and power after a while. so what may have felt powerful and fast for you a couple years ago it might feel slower now cause you got used to it.