Heishman

If you try the Accel COP's, let us know how they worked for you. Maybe I had a bad one in the 6 pack.

07bluelbz

So I went to O'Reilly and Advanced Auto looking for plugs and neither stock any plugs for my truck. It was also posted in this thread that an xp5364 was a colder plug but apparently that isn't correct. Autolite and Motorcraft get hotter in range as the part numbers get greater.What they came up with is that an xp5263 is a colder Autolite plug but I couldn't verify it so I didn't purchase them. They didn't list the NGK plugs talked about un this thread either. Anyone else experienced this?

RonD

Do a GOOGLE search for the spark plugs. Rockauto has them for $4. Jegs was about the same price, but they are now $9.

07bluelbz

I was mainly concerned with finding the right part numbers for the correct plug. Thanks for the info though.

11EB

Thanks for the info on this thread, got me curious. My 2011 Eco has 54000 miles. Mpgs aren't very good. I'm lucky to get 17 a tank these days mostly 15-16. I go through 1-2 tanks a week. Owners manual specs .033-.037 spark plug gap. Pulled mine out and all were .040-.042, pretty consistent. So I replaced them. It was hard to find oe plugs at the local parts stores, did find auto lite xp5363 but for the same price got motorcraft sp-528 at the dealer (~$8). The plugs were gapped at .035.
Why were they all out if spec? Let me know. Weird.
Engine seems a lot smoother. I was experiencing a " shudder" at heavy throttle about 3-5 rpm in 3rd and 4th gear. Gone. I've only put about 150 miles on the new plugs but I believe the mpgs are better. I'm at 19 but may be too soon to be conclusive.
Glad I did it, quite easy too!

maplelakeduckslayer

Anybody confirm that the 534's are what being run in the '13 trucks?

Went to a dealer and the part listed for '13 F150 was 528...other models with the 3.5L Eco were running the 534's but not the F150. Parts guy showed me the screen and everything.

f150man3.5

Same here

2011FX4boost

Same here

Rheller1

fordparts.com has them both listed for a 2013 f-150. I put the sp534's in my truck 1 week ago now. Nothing has changed, same gas mileage and same rough cold idle at startup. My original plugs were all gapped over .40. the 534's were all gapped at .35, and i gapped them down to .32. NOt sure what the difference is in the plugs. Mine originals were also WAY over torqued from factory! By the way, 23k miles and no shudder or loss of power.

Ford850

I noticed this about rough idle in the owners manual. It might be worth a try to disconnect the battery and go through these steps to reset the idle and fuel trim strategy:

"Because your vehicle’s engine is electronically controlled by a computer,
some control conditions are maintained by power from the battery. When
the battery is disconnected or a new battery is installed, the engine must
relearn its idle and fuel trim strategy for optimum driveability and
performance. Flexible fuel vehicles (FFV) must also relearn the ethanol
content of the fuel for optimum driveability and performance. To begin
this process:
1. With the vehicle at a complete stop, set the parking brake.
2. Put the gearshift in P (Park), turn off all accessories and start the
engine.
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Release the parking brake. With your foot on the brake pedal and with
the A/C on, put the vehicle in D (Drive) and allow the engine to idle for
at least one minute.
Note: If you do not allow the engine to relearn its idle trim, the idle
quality of your vehicle may be adversely affected until the idle trim is
eventually relearned.
7. Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16 kilometers) or more
to relearn the idle and fuel trim strategy along with the ethanol
content for flexible fuel vehicles.
• For flexible fuel vehicles, if you are operating on E85, you may
experience poor starts or an inability to start the engine and
driveability problems until the fuel trim and ethanol content
have been relearned."