Oil changes: 5,000 miles (conventional oil is only good for 3,000 miles, no matter what the manufacturer says; you need at least a synthetic blend to last 5,000 miles).
Transmission flush: 30,000 miles. * If you have not had your transmission flushed in over 80,000 miles, you run the risk of ruining your transmission by flushing it at this point do a drain and fill on the fluid not a flush (BIG DIFFERENCE).
Radiator flush: 100,000 miles or every 5 years (which ever comes first) The coolant becomes acidic, and will start corroding the inside of your radiator and motor.
Fuel filter: 15,000 miles. A lot of lost MPG if not maintained.
Power steering flush: 30,000 miles.
Air filter: 9,000 to 12,000 miles. You lose up to 10% of gas mileage with a clogged filter.
Cabin air filter: 15,000 - 30,000 miles.
P.C.V: 100,000 miles.
It's AMAZING how well these cars work if you just take care of them. These cars are built to perform, and if you slack on preventing problems before they start, you are doomed and will probably never get your Cougar back to where it used to be. You have to maintain it from day one. You absolutely cannot run it into the ground, and then be mad because you're having to shell out money to fix what you caused! Show your car some love.