Hmm Interesting, I get about 13 also and we do hardly any Idling, minimal amount of warm up ( less then 1 min), I changed out my plugs about 2K ago and I am using Bosch platinum +4, Replaced Air filter at same time with a Spectre HPR, I did just recently find out the Cat is Defective ( Got a code stating cat is unable to store oxygen). Would the CAT cause poor mileage? I would expect that if it was plugged but from what I understand it only is affecting its ability to reduce emissions. Tires are almost brand new Les Schwab Toyo Eclipse inflated at aprox 38 PSI. I personally can't think of anything else I could do to improve mileage besides adding a Bullydog Tuner device I have seen advertised on Speed and also seen on Stacy David's show on Gearz TV. Unfortunately all of our driving is in town never have any reason to do any long or medium distance freeway driving so I have no Idea of what mileage is there. I figure my mileage when I fill up I get miles off of trip meter and use gallons needed to fill it, I always fill it. I figured mileage every fill up for about 10 and it was always around 13-14 except in april when I first bought it before I changed plugs and air filter I was only getting 12MPG.

 

After running Lucas Gas Treatment thru the tank a few times my mileage is back to 20.

Bill

 

I also have a 05' T & C with 85xxx miles on it with a 3.8 engine. In the warm weather i get city driving 20, And highway 26.5 Now in the cold weather it drops quite a bit. How are you checking you mileage? Divide the gal's you put in two the miles you traveled will give you MPG. Mine has never been tuned up. I had a 00 Dodge van that got about the same with a 3.0 motor. So be sure your checking your mileage right hope this helps.

Rangr90

 

Yes I always ( at every Fill up) Take the Mileage on Dash Trip meter(Compared to EVIC Mileage Just to verify nothing was reset Incorrectly) and Divide it by the gallons Printed on Gas Reciept down to .01 ie 19.54 Gallons.
So I know I am doing it correctly not to mention every time it is about the same except the time when the 1/1 O2 Sensor had Kroaked then we were getting about 10Mpg. I have also realized the MPG listed on the EVIC Unit is approx 3MPG off stating we get 3MPG better then reality.
I am hoping maybe sometime I can find a reason to drive it down the freeway for about 100 miles or so and get an Idea of how much that changes it as we only do intown driving which already made me expect worse mileage then was statted but not this bad of mileage, I even changed oil at 2500Miles and made sure we are using 5W-20 oil and still no increase in mileage.

 

It sounds like your checking your mileage right. There is a big difference between your city mileage and mine. I think the worst i ever got was 15 and that was in the middle of winter and is to be expected. I think i would take it to a reliable Chrysler dealer and have them put it on there machine and check it all out like the timming and the timming advance and the fuel injuction and all that stuff to see if it is all within specks.
Hope you find your problem.
Good Luck.
Rangr90