I have a 2002 Trooper with about 83K miles on it. I bought the car used at Carmax with 26K mailes 3 years ago. I change the oil regulary and Air Filter. What other maintennace should be done at 83k miles ? I plan on changing the transmission fluid in the next few weeks. I spoke with a guy who works on Troopers he said a tune up plus,wires, etc should be needed until 90K Because it Has Platinum plugs, and don't flush radiator, timing belt should be fine until 100k. I am getting terrible mileage and with gas prices these days...It's killing me. I also got some high grade fuel injector cleaner from Bap Geon and have done that twice..Any suggestions would be appreciated..