Adobe2X

If 'twas an EcoBoost, I'd say change the plugs. With a 5.0, I suspect you are OK to closer to 60K.
If you are worried, take one or to out and look at them. If they look like my 6 plugs in the above post, you are good to go.

maplelakeduckslayer

If you are going through the effort of taking a look, replace them. I keep 2 new sets at home at all times, and I replace in the fall and spring which is 15-20k miles. It's about $20 in plugs why be stingy. Drink a few less beers a year. Misfires are BAD. You want to save $20 to gamble on it costing you 10k?

thekevin

What are the plugs of choice for the 5.0s.

Cord

I had a similar result with my plug changes. Now I'm only changing the offending plug and I've gotten almost 60k out of the second set. I get the dealer to read the computer and identify which cylinder is offending and order him to only change that one plug.

Schmidty_

general concensus is if your tuned, etc most guys are changing at 30K miles as a general maintenance.

VoiceOfReason

Understandably on vehicles where it is difficult to access all of the cylinders to remove the plugs, these vehicles would be exempt from the following: if you expect long reliable life out of your vehicle spark plugs should not be in service for more than 50,000 km. The cost to actively maintain the ignition system is so low it is foolish to stress the rest of the powertrain on aged components.

BTW, Ford made a bone head move by first installing the platinum plugs, and also without dielectric compound in the boots. The high resistance plugs, flaky coils and poor insulation is akin to driving a toaster through a car wash with a frayed power cord.

VoiceOfReason

I change my plugs about once a year (about 30,000 - 40,000 km) with Denso ITV20TT twin tip plugs at .030".

DesertPatriot

What does "add a can" mean?

QwkTrip

I think he was referring to an oil vapors separator catch can.

PSI-FX4

I have changed my plugs every 40,000 miles. Truck was running fine both times I've changed them, but I go ahead and do them anyways just for piece of mind.