ABOUT MERCURY MONTEGO MILEAGE

you can reset it and let it start over. If it never has been reset it would take a long time for it to change even a little it has had so long to learn the same driving habits. reset it while driving down the highway one day and it will start to avg. what your doing at that time and it will probably be much higher. The readout is not always that accurate if you let your car idle alot its averaging in a zero for mpg cuz your sitting still and that will make it much less. fill the tank and do the math on the mileage and that will be a better way to see what mileage your getting cuz the readout can be misleading sometimes.

I would check out the O2 sensor. You should be getting much better highway MPG's.

Its not an instant mpg readout on that tenspeed its an average. Like I said anytime you stop its averaging in a zero. like in grade school you know what a zero does to your grade average it kills it. it probably gets 25 or so on the highway but it wont show instanious fuel mileage it averages all driving conditions that vehicle goes through.

I believe it calculates an average mileage for the last 500 miles, kind of a rolling average. My 500 will say 19 mpg a lot when my wife drives it in town, but take a road trip in it for several hundred miles or so, and it gradually moves up into the low to mid 20's, depending on conditions, etc. Best I have seen it get is around 28 mpg on a trip to LA and back, around 800 miles round trip.

02 sensor: if wrong,should'nt the light show up? Also: how to reset the mileage to start over again?