I installed these last week and just wanted to give my 2 cents worth. So far these have been great plugs. I have noticed quicker throttle responce and I also got an extra 2 mpg per tank. These plugs were only 5.49 each at O'Reilly auto so they are quite a bit cheaper than NGK Iridium IX plugs. I know people say Autolites are junk but I honestly couldn't find any facts to support those opinions. The best thing about these plugs is that they are made right here in the USA so I am proud to be supporting American workers in these tough times.

Good deal then! I'll keep that in mind when I'm ready to change out my plugs.

How often should I replace my plugs? I'm at about 28k now

How often should I replace my plugs? I'm at about 28k now

Ford shipped all the LS motors with their Motorcraft Platinum plugs with the 100k mile "tune-up interval".

Myself, I've been changing the Motorcraft Platinums out for Bosch Platinum IR Fusion at about 50k miles and each of my FLM vehicles have seen a notable improvment in economy, response, and overall power. Keep in mind these ARE just spark plugs, it's not like pulling a Quik and installing a S/C, but the changes are noticable.

I've noticed that once the stock Motorcraft reach about 40k miles, the wear on the ground electrode becomes slightly/visablly uneven (the ground electrode IS the "wear item" of a spark plug). I believe this uneven wear to be the point when power and economy start dwindling slightly. It takes another 10-20k miles so the change to the new plugs is really noteworthy.

The Bosch Plat IR Fusions have four grounding electrodes versus the single one the Motorcaft Plats are equipped with. With the ground electrodes being the the part of the spark plug that wears, four has gotta be better than one, right? ;)

The iridium plugs are nice because the plug reaches it's self cleaning temp hundreds of percent faster than a standard platinum. Reaching the self cleaning temp faster means they are harder to foul out and therefore they last longer than what the manufacturers advertise as 100,000 miles between tuneups, so popping in a set of iriduims should have life beyond what the car ever would.

I can vouch for the stock plug electrode having uneven wear. I have 37k on mine so I decided to pull a plug to check the wear and was very surprised to see that it looked aweful. Took me about an hour to change those puppies. That was the longest it's ever taken me to change a set of plugs so hopefully I won't have to do it for awhile.

I have had denso iridium ever since I changed out all 8 coils for accels in the winter. Not a broblem since with either the coils or the plugs.

I am thinking about upgrading to the Accel coils. What part # did you use?

i'm using ngk iridium, one heat range cooler since i run nitrous. works good so far, have had them a year.