Hi, I have a 2002 Mustang GT. Mods include K&N Filtercharger, underdrive pulleys, off road x-pipe, Bassani cat back exhaust, and custom SCT tuner at 93 octane.
What spark plug should I buy for the most performance? I want to do a plug change before I hit the dragway this weekend.
While copper plugs have a hotter spark and are typically the least expensive type of plug, they do require much shorter change intervals. The 4.6 came with platinum plugs which should last about 100K miles, while the copper plugs should last between 10K and 30K miles.
If you don't mind doing the maintenance yourself and it makes you feel good knowing you have a hot spark, get the coppers. On the otherhand, if you are paying to have the service done/don't like doing your own maintenance, and could care less if your spark is not as hot, go with the platinum.