MPG drop after LONG time in storage

I have a 2005 Dodge Ram 1500, and it was averaging around 20MPG until I went to BACK TO BACK deployments. It has been sitting for awhile, and now I am gettting about 12MPG.

Where should I start? I used the fuel injector fluid that is poored directly into the gas tank, that boosts mpg for high mileage vehicles, but that hasn’t seemed to help. I do have a K&N air filter, should I clean that sucker? I havn’t cleaned that since I’ve had it (2008).

Could it be as simple as getting a Tune up?

I’m open to your words!

I would first check the thermostat to see it’s stuck open.


after sitting for so long you might have one, two, or more calipers hanging up (not fully releasing). This would put a drag on the drive train and decrease mpg.

Pull all the air intake duct work, you might have a mouse nest or spider nest block airflow. Result would be running rich and poor mpg.

Has your type of driving changed? I could see 20 mpg on the highway and 12 mpg in stop and go driving. Have you checked the tire pressure? If these are the original tires, they are due for replacement on age alone.

If a brake caliper is sticking, the wheel will get very hot after a short drive. I had sticking calipers on a 2000 Blazer after the pads were changed, the mpg dropped from 18 to 14.

By the way, thank you for serving.

Ed B.