My 2010 Ranger has 190k km was purchased with maintenance package that expired at 100km. Spark plugs were replaced at that time under terms of the maintenance package.
Now at 190k km, engine does not start like it used to, it takes longer cranking time. it runs fine but mileage is down from what it used to be. I'm wondering about fuel injector "cleaning" or intake manifold ports carboning up.
My career was in diesel powered heavy equipment.

 

Run a can of Seafoam or similar injector cleaner in the gas tank, I do this once a year.

Run that tank down to at least 1/4 before refilling
At about 1/2 tank you should notice a difference.

And time to change spark plugs
Check with local Ford dealers they often run "Tune up specials" to build traffic, its a free call :)
I get Motorcraft parts "on sale" for same or less than 3rd party plugs and wires

Also you should change fuel filters every 5 years or so
Air cleaner depends on location, once a year if in dusty areas

The PCV Valve is a pain to change on this engine but it should be done at least every 2 to 3 years, Ford says every year