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Plug Wires etc

Recently purchased 2004 Sport Trac with 104,000 miles. I have no maintenance records. Should I replace plugs and wires and anything else? Would like to get better gas mileage, any suggestions? The truck runs really good.

Thank you,

Your mileage on that vehicle will never get better than absolutely abysmal. See the attached ratings…

If it’s running great, just do the scheduled maintenance.

Unless you know the last time the fluidswere changed, I’d change them all. Oil, coolant, transmission, and rear axle.Also, the plugs, wires, and air filter. Start the clock from scratch.

But, you’ll only see 16 mpg if it is 2WD on a good day. Worse, like 12 mpg, in town.

I agree with @thesamemountainbike and @BustedKnuckles Many people hope that a “tune up” will improve their fuel economy, only to be disappointed when nothing changes. Now, if there was a misfire due to bad plugs and wires, that MIGHT be a different story.

@LarRose I don’t know what kind of driving you do, but here’s the factory maintenance schedule.

Take out 1 or 2 spark plugs and inspect them. If they look “worn” or have a lot of rusty corrosion on the base (where the ceramic and the metal meet) they are ready to replace. I think your motor may have coil on plug set up, meaning no plug wires.

Since this is a new vehicle to you, if in doubt about any service just do it. Meaning replace the plugs if you have no clue how old they are.

Since you don’t know the maintenance record…I’d replace the plugs…and all fluids. Start fresh.

Do you even have plug wires?? And as MB said…Don’t expect miracles in gas mileage.

My neighbor bought one of those, mainly to carry his kids bicycles.
He got the V8 4WD.
Loves the acceleration, loathes the mileage.
He gets a small break by running the tires 5psi over the door sticker.