There are a ton of things that can mangle your gas mileage. First - the tires, though not much taller than stock will move the power band up the RPM range (felt as a loss of power) & the engine actually needs to work harder at lower RPM to do the same work.

Second - the Cold Air Intake won't make it run lean - the computer & the mass air sensor read how much air is coming in & set the fuel mixture correctly. If the mass air sensor is dirty you could have bad fuel econ.

Third - You mention the rotors need to be replaced - if you have a sticky brake caliper it can suck the econ out of the engine & not be a noticable amount of drag. Raise it up on jack stands & spin the tires by hand. They should spin easily & have just a little drag. If they are sticky at all its the brake.

Fourth - If the torque converter in the tranny doesn't lock up you will have no power & really bad fuel econ. I could be wrong with the dodge tranny but a GM tranny will have a plug that if left off will prevent the converter from locking up at speed.

Finally - gas cap - i've heard of this but no experience first hand - if the cap doesn't seal the tank doesn't pressureize (??) & the computer makes adjustments to fuel pressure causing it to run rich. Again - I'm not so sure about this one.

Hope you find it - sucks to sell off your kids college just to buy gas.

 

Gears- gears, gears gears. But the convertor is an honorable mention. Mine flashes around 1500 RPM or so, which seems really low (especially for where ther powerband is), but is aimed for fuel economy.

This woulld be related to a bad OD-off sitch or tow/haul switch. But you would have a code for that, I believe. I know you would for a bad lockup solenoid.

 

4.7's are coil on plug and he said he did the plugs so that probably isn't it i would think it would throw a code if a coil pack was bad

 

like he said the cold air intake wouldn't really do it i wouldn't think and after a while the computer would relearn to adjust for the new filter...do you have the stock box tho maybe you could try it for ****s and giggles

 

Where is the mass air sensor and how would i go about cleaning it?

What is the standard checklist for fixing mpg?

I know i need new rotors because it hops when braking and the steering wheel shakes slightly at high speed braking.
although my tire say 31x10.5 in reality they are only 29 inches tall(same size as the last tires on it) they just might be a little wider.
I know my 02 sensors arnt defective because its not throwing a code!
Could worn ball joints cause bad mileage? I know the uppers are worn on the passenger yet they dont make any noise(they just clunk when i yank on the tire outwards)
I just want to make my mpg more managable, i would be happy with 14-15mpg if i could achieve it lol. 9 is not acceptable.

Also could my gas gauge be off? It fluctuates alot? maybe the gas tank is bad?

 

only true reading is to fill it until it clicks, log miles, fill it up until it clicks, take # of gallons, divide it out. That way you put the exact same amount of fuel in it both times, and you know the exact amount of consumed fuel.

 

Yeah thats right I totally forgot, I had a long sat night.

You can do the same with half a tank I did last night and I got 13.9 mpg thats all city.

 

Mass air sensor is on the intake between the filter & the throttle body. Large round thing with a couple of wires going through the middle.

To clean it - hit it with brake parts cleaner & if its really bad rub it with an emery board.

If you break one of the wires throw it away & buy a new one. Most places suggest just replacing & tell you they can't be cleaned. I've seen them cleaned though & if you are careful it can be done.

Don't mess around & sprak brake parts cleaner on a hot exhaust or use around heat though - it decomposes to a poison gas that can kill you standing.

Warn ball joints won't help mileage, but honestly they shouldn't effect it as much as say warn wheel bearings.

Measure your mileage this way.

Fill up the tank until the vent stops the pump. Don't top it off - just move on.

Set the trip meter & drive as long as you like - usually until you need more gas.

Fill up the tank until the ven stops the pump. Dont top it off.

Write down the number of gallons purchased on the second fill up. This is how much gas was used.

Divide that by the number of miles on the trip meter.

This will give the the miles per gallon for that tank of gas.

If you are measuring any other way - its your math thats off.

 

pretty much the long version of what I said, but it's what works!

 

alright i think i will clean it today when i change my oil.

Ill have to wait to test actual gas mileage but im pretty sure im getting 9-10 mpg. Now besides getting my build sheet how can i make sure my gas tank is the 24 gallon?(standard quad cab tank)