Is important to use the correct parts for your car.
You do not have a cap or rotor....is all computer controlled, solid state.
Go to
www.autozone.com for vehicle specific instructions on how to find and change items.
"Routine tuneup" items.
Spark plugs, get the correct Motorcraft replacement....my '96 uses a "DOUBLE platinum". Both the center and ground elements are platinum enhanced....is very important to use this for the windstar. Last I checked, only Motorcraft and Autolite listed a double platinum plug. Autozone stocked them under "stock code 686"....but check to make sure that you get the correct ones for your '95.
Fuel and air filters.
Verify that you do not have any vaccum leaks......
Look for loose vaccum hoses....make sure that you put the air intake back together correctly....etc.
If your spark plug wires are the originals, you may need to replace them also.
A good quality fuel system cleaner, such as Redline, Cheveron "Techron", Fuel Power. This is to clean your fuel system, including the fuel injectors. If you have not done this for a while....give it 2 treatments back to back. There is not enough detergent in the gasoline to keep things clean.
If you are handy...cleaning the MAF (Mass Airflow Sensor) with non-residue electronic cleaner may help.
PCV valve.....get motorcraft to be sure that it has the correct flow rate.
Change the anti-freeze. Use the standard ethyline-glycol coolant. I am not big on "long life" coolant for our cars. If you decide to use a long life coolant....you must flush ALL the old coolant out before putting long life coolant in....as it is not compatible with the normal stuff. Prestone has a new long life coolant out that claims to be compatible with other coolants....but all I know is what they advertise. I have the Prestone ethyline glycol coolant that comes in the yellow bottle. They also have a "pre-mixed" coolant which is good for top-off.....or if you have not flushed with water (as you would still have a lot of water in the system from the flushing...to dilute it down).
I have not done any major flushing of my cooling system. If you do any "power flush", FORD has a TSB that states that the heater core must be flushed separately to avoid clogging it with stuff that may be worked loose by power flushing. That would require disconnection of both heater hoses.....etc...more work.
Make sure that you register heat on the temp. gauge.....the tempurature should cycle up and down slightly as you drive....more so sitting at idle.
Check the battery and terminal connections....If the battery is 5 or more years old....you could be living on borrowed time. A battery that is weak could be drawing a charging current all the time....which is additional load on the engine.....
Another thing to look for.....would be a dragging brake. This could be on the front or rear.
Your rear brakes auto-adjust when you use your parking brake.
Verify that you have the correct tire pressure.
In the cold weather in Wisconsin.....I normally see a drop in fuel economy. Also, there is a different formulation for gasoline for the winter.