Lousy gas mileage, (12-13 mpg). Had it looked at by the dealer three times, and nothing has changed. (In-town use almost exclusively. In-town mileage was listed at 18-24 mpg by the manufacturer. Nothing seems to be mechanically wrong with it.)
Has a fuel trim test been done? If the fuel trim is ok, most likely
- that’s just the mpg you get w/this vehicle given your driving style; or
- you are not measuring the mpg accurately
My daily-driver truck gets 15 mpg, normal, somehow I just live with it.
You drive only in the city, EPA city rating is 18 mpg. That is an estimate. Your experience is 35% less.
The biggest factor in fuel mileage is the driver. If the dealer finds no issues with the van, it is likely your driving style.
Some things that can cause poor mileage.
A thermostat that’s stuck open.
A faulty coolant temp sensor.
Tester
Add a sticking brake caliper to Tester’s list. You can check for that by seeing if one wheel is much hotter than the others after driving.
Did you used to get better milage? How much?