Getting near 90,000 mark so I asked my local dealer when should I change plugs he said at 100,000 but I did a sneak peak at the plugs gap was up to 58 high speed glazing on the top.Can't wait any longer what are the best spark plugs on the market for this mammoth creature?

 

Platinum tipped plugs.

 

Stock ones are just fine. Look how long they lasted you!

 

So what's the best way to change the plugs? I've never owned a vehicle so technically-advanced; or one with so many spark plugs! I changed the plugs in the Mini today; took 5 minutes. I don't even recognize half the "stuff" in the X's engine compartment.

 

Doing mine for the first time checked one took me 21 mins total time anybody got any shortcuts or suggestions.

 

Keep your afternoon clear.

Which one was that that took 21 minutes?

 

The Motorcraft platinums are the best plugs for your truck. Do not get Bosch platinums, they will not preform well in this application. Bank 2 (drivers side) is not to bad to do, bank 1 (passenger side) rear most plugs are really tough to access. I believe you need to remove the fuel rail on that side.

 

Too late bosch it is no trouble yet gapped @0.54 instant results went from 11mpg to 13.7mpg. The total time was one hour on the driver side one hour fifty minutes on the passenger side I just unloosened the fuel rail on each side so I could get to the coil off easy price the coil at local parts store $49.00 PER COIL. Didn't get autolite had bad encounter on my mustang.

 

If the coils haven't failed is it required to change them when the plugs are replaced? Assume they either work or they don't, would a check egine light come on if a coil failed? With the V10 you may not feel a single failure, although you would see gas milage drop a bit?

Thanks...

 

Yes the check engine light will come on becuse it is in the scan code but which say that a cylinder is gone.B ut yes a v10 won't feel it

 

Would not change coil unless they looked bad like ( busted boot,real loose spring,etc...)

 

If it ain't broke, don't fix it. Engine light may or may not come on, and it can even come on and go away. I drove my truck several thousand miles, only to find that one of the coils was arcing like a lightning bolt. I never saw it. My Ford truck mechanic friend saw it and replaced it, and the problem went away. No codes or anything. Just that intermittent engine light. That one coil cost me $145, from the dealer. Only spend what you need to, since eight coils would sit over a thousand. Plugs? Just change them on the 100,000 mark. It's rare that one goes bad, but it does happen. Mileage will suffer if it is just spitting gas and not burning it, but it may not be as noticeable unless you do as I do, and spend too much time watching the mileage display. During the cooties pandemic, I drove to the interstate and back, early in the morning, for a couple years. Gas was cheap and the idiot drivers were all at home wearing their masks and fearing the Fauci gods, so I got to watch my mileage over the same course. That was when the engine light came on and off, several times. I noticed a small mileage drop.