[ciderbarrel]

To go from 17 MPG to 20 MPG means that you're changing your fuel consumption from 5.88 G/100 miles to 5 G/100 miles. Consuming 0.88 gallons less over 100 miles might be doable but it is going to be tricky on an automatic. I would run the cruise control as much as possible.

Always coast up to red lights, and try to learn the timing of the lights on your frequent routes. On the way to my supermarket, no matter how hard I try, I will always get stuck by a light down the road after I make a left turn. I just keep it 5 under the limit and by the time I arrive at the 2nd light, it is turning green, and I never had to hit my breaks as I just coast to the light. Keeps my fuel consumption low.

Once I get a few more tanks to have a better collection of data points, I'm going to start a thread about how I've taken my 4.6L Mustang from a 20.5 MPG lifetime average (4.88 G/100M) to 23 MPG (4.35 G/100M) on my last tank (and 23.9 half way through this current tank, in winter). That is a savings of about half a gallon of gas per 100 miles. Short of turning the engine off while moving, I don't see what else I could do other than to drive 95% of the time on highways where I can get 28-30 MPG depending speed my speed and the grade of the road.

I am running an ultraguage, tires at 10% over max PSI, and keeping only 5-7 over the limit on the highways. You have to in my area as 70% of the traffic moves at 10 over the limit, even in the slow lanes. Someone in my are just got a ticket for going TWO mph ___UNDER___ the limit a couple days ago. I also took out the cold air intake (CAI), and put in the stock airbox.