5.2 fuel problems
 

My 99' Dakota is great but my fuel millage is horrible. About 300klm to a tank. Is that normal or could there be something that i can do to help it?

I get around 300mi to a tank (filling at 1/4 or a little less). Are you driving normal or are you running it hard?

If its been a slow decline then Id start with preventative maintenance (tire pressure, plugs, wires, cap and rotor, air filter ect).

300 kilometers is about 186 miles.

I'm curious as to how many gallons (or liters) a typical fillup is, that way we can know what your actual MPG is.

You can do a tune up (plugs, wires, air filter, oil change). Check your tire pressure.
Others have had luck when they replaced their oxygen (O2) sensors, or their Manifold Absolute Pressure (MAP) sensors.

Ture.


How many gallons are you putting in each fill up and what miles during which?

Damn 300 mi on a tank. Im getting about 150-180 a tank

Distance per tank is useless. MPG and KMPG is what's important. Drive X distance, fill up, divide distance driven by gallons used, then make an assessment of your fuel mileage.
But FWIW I can get over 400 miles out of a tank on the freeway at 20+MPG.

I think my mpg is bad I figured 8mpg couple times this is what my friend is getting in his lifted ram.

I have the 5.2 auto 4x4 3.92's turning 31's all stock except for exhaust average 8-12mpg
Attachment 99140


His truck 5.2 auto 4x4 3.92's k&n and exhaust with a lift turning 35's average 8-10mpg
Attachment 99141

If you ask me something is wrong with my truck or he gets awesome mpg for that truck but I know thats not the case.

31s with 3.92s is pretty much perfect gearing, no problem there. The automatic doesn't help. Where do you drive? The worst I've ever gotten out my truck was a little over 13MPG when the tranny was bad when I bought it and couldn't use 5th. I drive 50% country roads, 40% town/city and 10% highway on my average tank and typically get 14.5-15.5 now that I have 5th gear. I've even gotten 15MPG after spending 4 hours driving around in the forest.. If I spent my whole time in town and city I'd expect about 12MPG.

I live in a very small town it has 1 stop light and is pretty flat I dont drive any further than 10mi or so normally about 45 mi once a week which its a mountain but its only about 5mi long and my rpms are about 2000-2,300 then its back to 1,500 which when im driving I try very had to keep it there.

Have you tried changing your O2 sensors, and MAP sensor?
Another thing that can have an effect on MPGs is the engine coolant temperature sensor (depending on year, the engine may have two sensors, one on the left and one on the right side of the upper coolant hose)