hi, I've got a 2003 300m with a 3.5L HO engine and am not very happy with the milage. What is everyone else getting for milage, i am getting only about 22 MPG highway so was wondering if there is anything i can do to improve the milage such as a computer chip. Also is there any possibility that something may be wrong with the car causing it to get worse milage, however, mechanically the car is fine.

 

I doubt the car is "fine" if that is your MPG...I easily get 26-27mpg on the highway going 75-80mph (with the A/C off). Perhaps it is time for a tune-up...?

 

I have the 2.7 L engine in a 2001 Concordeand only get 25-26 on the highway. I would suspect that the HO engine would suck down more fuel. 22 MPG sounds about right to me...

Bill