What is your luck running different plugs? And what do you think is the best one out there for our trucks..both in the 4.6 and 5.4

 

oem, just make sure you check the gap.

 

I changed the original plugs and wires 3500 miles ago using Autolite APP104'S. My 1998 4.6L F150 2WD had 112,000 miles at the time and it's been running much better every since. Smoother with more power. The mileage went back up to 16 in town (same as when it was new) I believe the wires should be done at the same time as the plugs, by the time you get done pulling on those wires there's going to be a break in them somewhere.

 

The head wrench at the local Dealer said I could buy the plugs to save money, but he would not install anything but MotorCraft. He said it was not a Corporate thing; he'd just had poor results from all the other plugs.

I took the truck to my favorite wrench (Non-Dealer), and they strongly recommended Motorcraft plugs, which they don't "sell". So, I did. Idle was immediately smoother, and the engine seems to pull stronger, although that may be because it doesn't have the former weight of my wallet to haul.

Go with the Double Platinums. I think OEM is(was) single platinum. The doubles should last quite a while.

BTW, I bought the plugs at the Lincoln dealership at a discount