[wiswind]

Too rich or too lean is bad.
That is why the system maintains the 14:1 air to fuel ratio.
To add lubrication to the fuel, you can use a fuel add......a cleaner like Redline S-1 fuel system cleaner has lubricants......so you would use it in the "maintenance" dose with each fill up.
I have also used Schaeffer "Soy Ultra" as instructed in a maintenance dose....a couple of ounces per tankful of gasoline.

Lucas Fuel treatment claims to do the same, though I have not used it.

I have read that you can also use 2 cylce oil as long as it meets NMMA TC-W3 .....It will say so on the bottle if it does.
I read about it on Bobistheoilguy forum, but NO MORE than 2-3 ounces per tank of gasoline or it will cause problems.
I have not used this either.

Personaly, I would add the Redline, Soy Ultra, or similar product in a "maintenance" dose with each fill up, if I want to add lubrication and some cleaning ability to the fuel.

As a note......adding these products has NOT gotten me around having to add Berryman's B-12 Chemtool a couple times a year.
I would NOT use this product in every fillup.....just once in a while.
I don't know if all years of windstar have the same issue with the fuel injectors as my '96.

The fuel that my vehicle gets is almost ALL with the 10% ethanol........as all the stations in my area (as with many areas of the USA) are required to have this fuel.
I get a occassional fill up of "normal" fuel when traveling.

As another note......don't overlook replacing the fuel filter every year or every other year, depending upon how much you drive.
A clogged fuel filter may cause a major increase in workload for the fuel pump for some time before you see any drivability issues due to the restriction to flow.