I heard the rule of thumb is 10.000 miles. Is that an over kill? I know the best is to check them, but by the time you check all eight plugs, you might as well change them since you are already half way there>

 

ANyone out there?

 

I believe that there are a lot of different rules of thumb out there. I change mine at 15,000 mile intervals. I have no idea how Ford's rule of thumb became 100,000 miles. They may go that long but the performance standard went a LONG, LONG time before that.

 

i got the denso's in about 1500 miles ago...and they will be checked or replaced in about 5-7000 miles...

 

Lets see....

0-700 miles with the stock ones...
700-4300 with some NGK that JL sold way back
4300-13000 with some Denso IT 20's
10000-19000 with some Denso IT 24's
19000-234??? with some NGK TR6's
234??-????? with the NGK BR7's

6 sets of plugs in less than 25K.....

 

Rich, you change your plugs so often because you are always uppgrading your mods right?

 

Not really... Its more along the lines of pay alittle now or alot later... I have only changed boost levels twice.

 

Leemee see...........Alot of people say they are always blowing out. 34,000 miles........and none have blown out. I'm going to see how many miles that I can go without blowing out any plugs? Who knows ? I may not change them for quite some time.

I'll have to see what the owners manual says about mileage for changing them?

 

Not really.

High performance vehicle = higher maintenance.

I plan on changing mine every 10k miles, or sooner if insepection calls for it.

 

I have 10,000 miles on a set of Denso IT 22s. I pulled them because I figured they were gone. They were really good, only #2 look kind of bad. I cleaned them up, checked the gap, and put them back in leaving the NGKs I bought for later. The bad deal I found was 2 plugs loose and 1 not very tight. I will be checking more often.

 

I changed my stock plugs at 5 or 6000 miles and two were loose.
500-800 more miles and I burnt up (3) TR-6's due to a clogged fuel filter. Again one was so so in the tight department. Two months ago I switched to Denso IT-22's and put those suckers in as tight as I could possibaly go and plan on checking them again in the spring.

If you talk to Sal of PSP he'll tell you he has seen many loose factory plugs on new L's when he does a customer Plug change.
My best guess here is check or change them twice a year to be safe, I already have a new set of Denso IT-22's sitting here for next time.

 

Rich,
Just curious why you went from the Denso's to the NGK's? It seems to be the consensus around here that the Denso's are the better plug even though they are alot more $.