I have a 96 Grand Caravan with the 3.8l engine. I recently replaced the spark plugs and wires, air filter and new tires. Doing the math after filling up at the gas station I am getting about 13.5 mpg during city driving (my overhead says 13.0). I have been using the A/C a little but not all the time, maybe 25% of the time or less this past month.
Does that seem about right? The window sticker says it should be 16/18 mpg city driving. Just wonder what every one else seems to be getting? Any tips or tricks to get better gas mileage? Maybe replace the O2 sensor?

 

I've got the same van/engine and am getting 23-24 on the highway. Can't give you a good city figure since we don't do much city driving. The best I can say is at 75% highway and 25% city we get 20 - 21. 13.5 does seem a tad low but can't see anyone getting close to 18 in 100% city driving.

Tips? Play the lights. Look well ahead and consider traffic conditions as you take your foot off the gas coasting to red lights. Not using seats often? Take them out. Keep tire pressures and alignments to spec. If components are a concern spark plugs and O2 sensors would be high on my list especially the later if well over 100K miles. I've read of some having success just cleaning them.

 

Our 2nd gen with the 3.3L averages 24mpg in mixed, around 20 city only.
Our 2nd gen with the 3.0L averages 25mpg mixed, haven't ran all city to see.

13 seems incredibly low. My friend's 98 grand with the 3.8 averages low 20s, 17 city.