Hello All, I have a 2006 Dodge Dakota V8 4-door, that takes regular gasoline.
This beauty of a truck has been in Canada all its life. She has 350,000 km (215,000 miles) and runs like a champ. Except that lately, it's been consuming fuel like crazy.
When I got the truck, at 300,000km a full tank of gas would last me about 400km (250 miles), now it's more like 250km (155 miles). I've kept track of this manually by recording each fill-up.
I've replaced the spark plugs at 330,000km, and I run fuel injector cleaners every 5,000km or so, these would improve the consumption for a while, but then it would drop again.
No engine light is on the dash, and no leaks are found anywhere. The truck sounds great and runs properly. It's a tank, it has never given me any issues in winter or summer and turns over every time.
I wonder if maybe there is a problem with the fuel pump, or if somehow the ECU is making the car run rich in winter?
Do any of you have experience with this? Any advice is welcome. Thanks.

 

Gas mileage will decline in the winter months..... Winter blend fuels are notorious for that. Still, it shouldn't be THAT drastic of a change. If the O2 sensors are original, I would seriously consider replacing the front sensors. (don't know how many you actually have, could be one, could be two...) Use only NTK or denso sensors though. These trucks just don't like the other brands. Reset the PCM when you change 'em, and be aware, they've been in the a while, and are going to be VERY reluctant to come out.

 

In addition to the winter fuel change, my "tank-to-tank" mileage drops in the winter because I have remote start and I like to run the truck for 5-10 minutes to warm the cab a little before leaving the house. But, it's not as drastic of a difference as you're describing. In addition to the sensors, maybe check to see if it is throwing any codes.