04CompetitionOrange

I don't have an owner's manual and I couldn't find the info doing a search....when does ford recommend changing the spark plugs?

I am changing my oil in the morning and was thinking about changing my plugs too. I have 87K on the clock....no missfires and the car runs great.

ct_white_stang

I think the 100K mark is the recommended time.

mustangcat

I was thinking more along the lines of every 25-30k miles. So yes, now would be a good time to check them.

teej281

id say unless youre having problems, why fix it. When you do have a problem, then you change them and upgrade. My motor, when it went, had 92000 miles on it and had the original spark plugs and they were just fine. Put them in the new car til i put TR6's in it. But if you wanna do the upgrade, buy yourself some NGK TR6's. They are cheap and an all around great plug.

cliffyk

The factory spec is 100k miles. The OEM plugs are single platinum (center electrode as the current flow is conventional tip to side-wire), and the stock COPs have plenty of power to fire 'em for that long.

Here's the maintenance schedule from the 03/04 shop manual...

03BottleFedGT

i had to do mine at 50,000. it really depends on how your car has been driven and the fuel you run. when i worked at ford some went 40,000 some went 100,000 it just depends. i would go ahead and do them if your above 80,000, but dont use the tr6's in your car youll be better off using an autolight platnium plug ap104 or an autolight double platnium app104. just my 2 cents.

youkairyu32

I am totally different... lol I probably change mine every 10k miles or less. I know that it will keep running on the old plugs just fine, but I swear I feel a few hp of difference when I change them. But then again... I have upgraded spark coil packs, so that may have something to do with it.

teej281

why not use a TR6???

mrsinister2424

Its in your head buddy, you can't feel a "few" hp

03BottleFedGT

tr6's are only recomended to use if you have a power adder they are a step colder than stock. i use them in my new motor because im spraying it but with a stock n/a motor they are not recomended