What a difference replacing spark plugs and wires can make.

Truck is a 2006 XL with the 4.2 under the hood.

80K miles on it, and to the best of my knowledge plugs and wires had never been done on it.

So, last week I decided to replace them.

Went with Motorcraft OE platinum plugs and BWD(Borg Warner) wires from O'Reilly.

Tank of gas previous to replacing plugs and wires, I was way down around 12-13mpg average on the tank with mixed highway and city driving.

After replacing the plugs and wires, I'm back up to around 16mpg average so far.

Amazing the difference this made.

Old plugs were worn out. They'd been in there so long they were at .075 to .080 when I measured the gap on them when they came out. New plugs were gapped at .054, right in the middle of the recommended gap of .052-.056 by Mitchell OnDemand at work.

Fuel filter is next. Probably within the next 2 weeks.

 

After 60,000 miles my Motorcraft Plats were out to .065. I knocked them back down a bit and hope to get another 20K out of them

 

I got 84k out of the originals on mine, so you did the right thing at the right time. The only difference is I used OEM Motorcraft wires too.

 

.075 to .080? Glad you got some new plugs

 

Yeah, they were flat-out worn out.