I have a 2008 Ford Escape 2008 2.3l, 4 cil, 4wd. Need to ask about the consumption, read below?

When I bought it was giving me 22 miles/gallon combine, and more or less 19 miles/gallon in city. Now it gives me between 16 and 19 miles/gallon combine and 13 miles/gallon in city.

What could be wrong that it consuming mote gas?

Get a tune up and check for vacuum leaks. Have a mechanic check the engine with a diagnostic machine.

Are you doing your own oil changes? How much air in the tires? Checked your transmission fluid? Transfer case/diff fluids? What's the average distance you drive? How are your brakes and wheel bearings? Engine mounts? In short, anything that makes it harder for the engine to turn, motion to transfer to wheels and wheels to turn over will have an impact on the fuel economy.

I would start with fuel and oil - make sure you are filling up at a reputable station and using the correct oil weight/amount. Try a full synthetic at a manufacturers recommended 5W-20 (if I recall correctly). Make sure your tires are properly inflated, are they making any noises as they turn over? Any odd wear on the tires? Are the brake pads wearing evenly or is one guide pin stuck dragging the brakes? Your generation of cars is prone to transmission issues - not the best box Ford built, get it checked.