DILO2001GT

yeah i also don't know i have had my car for 60k miles and i haven't replaced them lol. how dooooo you know you need them. also which ones.

Soaring

Take one or two out and check the gap. If it has changed to something like 0.60 and it is obvious the electrode is burned, it's time for a change. A general rule of the thumb is to change them at 30,000 miles.

racer02GTstang

i got some new bosch platinum 4's just now... they are nice... took about 1- 1.5 hours to install. cause of i had to take a break to eat some dinner. car runs much smoother. i forgot to put one of the plugs back on and i thought i had rough idle cams in there atfirst. it was rough. so i put it on and it runs smoother. i feel alittle smoother accel also. now over the next couple weeks i will find out if my mileage jumped.