'99 Camry/Poor Gas Mileage
 

I have owned my 1999 Camry LE (4 cyl/Auto)for 2 years. It now has 110k miles and still runs like a top. I have seen a rather drastic drop in gas mileage in the last 4-6 months; about 4-6 mpg. I used to get 26-28 around town and 30+ on the road. I have changed the air filter and spark plus (OEM), didn't seem to make any difference. The plugs that were in the car were not fouled or burning rich. The automatic choke seems to be running awfully high during the summer when first starting the car. I run Mobile 1 oil and filter and drive very conservatively. I would appreciate any thoughts on where the problem could lie?