problems with city gas mileage.

I have a Venture 2000 (odometer reading: 93000 miles).
Recently (like all of us:)) I started paying more attention to the gas mileage.
Highway is fine, I am getting around 24 mpg.
City is much worse; I am getting no more than 12 mpg.

I wonder if cleaning injectors with a concentrated cleaner solution added to the fuel would improve my city mileage.

Will appreciate any feedback.

Hard to believe you are only getting 12mpg in the City, unless you are driving in Manhattan the whole time with a van full of people. After I double-checked my math, I'd get my codes read. You might have a bad oxygen sensor which can really cut into your MPGs. If you don't have a reader, Autozone will read them for free. If you haven't done so already, you are very close to the 100,000 mile recommended spark plug replacement time, although I assume you'd notice if the engine felt like it was misfiring due to a fouled plug. Using a concentrated fuel injector cleaner once in a while is always a good idea in my opinion.

Thanks for the tips.
There was no check engine light on. Oxygen sensor also was fine.
My mechanic diagnosed the problem as dirthy air filter. I hope this will help.
Thanks

Hard to believe you are only getting 12mpg in the City, unless you are driving in Manhattan the whole time with a van full of people. After I double-checked my math, I'd get my codes read. You might have a bad oxygen sensor which can really cut into your MPGs. If you don't have a reader, Autozone will read them for free. If you haven't done so already, you are very close to the 100,000 mile recommended spark plug replacement time, although I assume you'd notice if the engine felt like it was misfiring due to a fouled plug. Using a concentrated fuel injector cleaner once in a while is always a good idea in my opinion.

Thanks for for your advices.
I han no Check Engine light on in the dashboard.
When I was getting inspection recently, I complained about poor gas mileage. The mechanic checked both oxygen sensors and said that they were fine (he mentioned something about correct voltage switching values). He changed engine filter and said that it should help. The car passed the inspection without any problems.
500 miles later, city gas mileage is still poor.
I assume, that if something was wrong with the oxygen sensors the car wouldn't pass the inspection. Does it sound right?