Oh mines a limited and it has an overhead console on it and it reads out the instant MPG, and the average.. You can adjust it every time you fill up, to calculate it when you fill the tank up...

The manual way i did it was to:
-Run the tank till the Gas Light comes on
-Then refill the tank to half a tank or so, and take note of how much fuel i put in it
-Then i reset the odometer to count the miles run until the gas light comes on again
-Then i divided the two numbers, and it gave me the average of the Highway miles that i drive and the City miles...

But i normally just use the overhead console...

Oh and no-one seemed to answer my question on how to determine if the Oxygen Senors are wrong... Does the check engine light normally come on when they are bad, or do you just need to hook a computer reader thing up to it, and see if it throws up a code...?

 

02's ususally throw a code. but there are some cases when... lets say the heating element in the 02 is not working. the motor will never go into a closed loop. this may not throw a code but it is a problem.

when u start any vehicle up after its been sittin for a while, it starts in an open loop mode. during this time the motor is running rich and is idling higher, until the 02 senses that the exhaust gasses have heated up enough to close the loop and idle down the motor for normal driving. that is in affect what happens everytime u start ur car. short version.

now when the 02's heating element has failed the open loop never closes. thus stayin in a rich mode. as u may nor may not know running rich is to save the motor from detonation but it eats up gas. when the sensing bulb get up to 600* i think it is... it will close the loop and lean out the fuel. so if all seems to be good. tune-up has been done and ur cat is good. etc... and ur still havin the same mpg problem change out the bank 1 02 sensor clear any codes u may have and see what happens.

i hope this helped. btw stay away from aftermarket 02 sensors. only go with the mopar. our jeeps dont like them at all.

 

They weren't attached to the Jeep, and I don't have renters insurance like a moron.

 

Well I can't tell if the motor is running rich. But I will surely pay attention. But there is one thing that I does every now and then. When turning the engine off then recranking it a few minutes later. It will have a weird idle until u press the gas for a few seconds. Not sure if that is a sign of a bad one or not, but I figured I'd ask.....

 

do you have a leaky injector or 2? sounds like you might have bad pressure...if after it sits and hwne u fire it up, the pressure might really expose the leak, making it run funky...happened to me

 

See I wondered that myself. I thought that maybe since my MPG is so low that maybe there could be a problem with the fuel pump or maybe the fuel filter. But I haven't had time to change either one. But I've been told that the fuel pump and filter is in the gas tank. Which is one of the main reasons I haven't checked it yet.

Maybe its another possibility, love to find the real problem....

 

My fuel filter is not in the tank.

 

Is the location different between models?

 

I don't know about models, but maybe years?

 

Yeah what I ment. My bad. But ill do more research. Is what I turn up. Where's yours located?

 

I know on my 2000 its build into the top of the fuel pump, like so

 

Above my drivers side rear tire.



Here:

 

Top middle of the pic if I'm not mistaken...

 

thats it. I like the external filters better.

 

Well if it werent for me having to go up steep hills and steep backroads Id be doing better than 12-14 mpg. hills. On the highway I do around 18ish...I generally try to stay under 65 mph and coast whenever possible like on downhill slopes of the highway.