My 2.4 Liter Stratus is turning 300K (miles) fairly soon and she is getting around 29MPG (highway). But the power is lacking and oil is leaking (a quart every two weeks). I swear I use to get 33-35mpg but with time I have lost MPG somehow. My question is how do I get her back in shape and competitive with newer vehicles getting better gas mileage? Any ideas/suggestions/comments are welcomed.
Thanks!

 

Sadly, there may not be much you can do.

Leaking that much oil, I would track it down and get that fixed first. To get her back up to snuff, you may need to replace pistons of piston rings, reline the cylinders, or other drastic work to get the compression back to what it's supposed to be. The metal expands and stresses over the years, and having that many miles on it (not to count the hours spent idling and NOT moving), that's a LOT of mini explosions in those cylinders.

Your transmission is probably wearing down too, especially if you've not kept up on fluid changes, and worn fluid will keep the power that your engine is making, from getting to the wheels.

 

It's probably the 10% ethanol in the fuel. That reduces gas mileage. Fix the leak and drive that sucker another 300K.

 

At 300K, your car sure is a fighter! Like mine, I may recommend an overhaul. Check all the wiring and make sure none of it is cracking and fraying apart. And as said, a car with this many miles is due for new piston rings and probably gaskets. With a car this broken in, anything that creates a seal pretty much should be checked and replaced if necessary.

 

I got 362000 on my 2.0 and i just keep good plugs and wires on it and run her !! A quart of oil every 2 weeks aint nuthin !!