Mitsubishi Repair: Is it my trany?, fuel mileage, gas mileage

Question
I own a 03 lancer ES Lately I have noticed that my gas mileage is much lower than it should be, my RPM's are running at about 3000 at highway speeds when they are normally 2500 unless I get up to 75/80mph but this is at 65mph, My Trans fluid is fairly new, I ask the tech's to also change the filter. my car seems to run fine up till 3rd gear, only after does it seem to have a hard time.and there is no check engine light. any idea on why this is happening thanks - Dawn

Answer
Dawn: You asked the tech to change the filter but to do that he would have to change the fluid too. So did he do these things? Are you running the right kind of fluid for your car, these little cars take a more costly fluid and I am seeing that a lot of people don't bother to use the costly fluid but go with a cheaper kind and that just does not work. Because of the heat that these transmissions kick out they need a fluid that will not break down with higher temps. I still would have the car's computer coded just to see if the computer might kick out some kind of reading as to a problem with the gears from third gear up. Are you sure the car is shifting past third gear? Because if there is a problem in the transmission and the computer finds it, the computer will lock the transmission in third gear. It is called a safety mode, it is the computer's way to save the transmission. In these newer cars the computer controls a lot of things in the way that transmission shifts with the help of many sensors. As I re-read your email, I bet the transmission is not shifting up through the gears but is already in that safety mode because of the higher RPM. You need to get this car into a transmission shop and find out what is going on with it. Or have that tech check things out, because you have a large problem here. Please don't put it off.

With your fuel mileage I would get the fuel pump tested to make sure it is putting out enough pressure to keep the car zipping down the road. You know don't you that the fuel is what keeps the pump cool? If you run your car down to empty to much, with time you will cook the fuel pump. Seeing a lot of pumps being replaced these days due to that high cost of fuel, everyone wants to get as much as they can from that tank of fuel. But your fuel problems might be due to the fact that the transmission of your car is not shifting as it should, so that is making the engine run harder and there would be your fuel problem. Please don't put this off, get your car checked out as soon as you can. Hope this helps and God bless: Linda