Poor gas mileage
 

Why is my daughters 03 Neon SXT only getting around 20 MPG. Car has under 40K on it.

Does it need a tune-up?
https://dodgeforum.com/forum/2508248-post2.html

Poor gas mileage
 

Have changed plugs and air filter so far.

Mine seems to be getting poor mileage too. I'm only getting about 300 miles to 1 tank. I've replaced the valve cover gasket (unrelated issue), PCV, Spark Plugs, Spark Plug Wires, Air Filter looks clean.... I got about 28 miles to the gallon the first week after I bought it but now getting very poor gas mileage... Any ideas?

I only get 220-250 miles per tank. It depends on where/how you are driving and if the car is properly maintained. I live in the mountains (steep grades everywhere), there is nowhere to maintain a constant speed and the average driving speed is not very high. If I'm on the highway out of town and can maintain speed, I'll get into the mid-30's for gas mileage.

I have a standard neon with auto trans. I have been getting 30 mpg average all summer using the A/C and 32 mpg in the winter with no A/C.

Wow Ok... I would be getting about the same as you then. I haven't taken it out of town yet so not sure what the highway mileage is...

think you are all getting better than me, just picked up a 05 a/t with 100k and only getting 25t on the highway max, any body seen noticeable gains with free flowing muffler, accel/msd coil

Stock coil is just fine. Change the plugs and wires and get a drop in K&N style filter. For the plugs just get copper plugs and properly gap them. Getting wires with a lifetime warranty will save you money in the long run. I change my plugs/wires every 6 months and it only costs me $10. A free flowing muffler or no muffler will also help gas mileage some, it'll just be loud. Since you have 100k on the car, the timing belt/water pump need to be changed if it hasn't already. I have a 2000 with the 3 speed auto and get 30 city driving like I stole it, 32-33 city when I drive like a grandma. I get 40 on the highway doing 80-85. I don't have A/C so the windows are always down.

I dont get any where near that with my 2001 auto se. Well it depends I guess.
When I have filled it recently I ended up getting 143-150 miles with the line a little below half. Which wouldnt be too bad if i could do the same amount of mpg on under half tank.
I went to the gas station and filled it back up adding 7.xx gallons.

Usually as the line drops below half it seems like the mpg drops any one get what I mean?