[tygercsw]

I purchased a 2013 Dodge Dart Aero in March with only 2500 miles on it. It's been fantastic and I've averaged 33-36mpg city/hwy combined.

I had an oil change done on it 2 weeks ago for the first time since I purchased it (10k miles). When I drove the car into the shop, my MPG was at an average of 34. When they were done and I turned my car on, it said 29mpg! I thought maybe it had to do with the computer or something, so I went on my way. It never corrected. Ironically, they also said my tire pressure was too high so they took some air out. Odd...

A few days later I get a "tire pressure low" warning out of the blue, so I stop back in. They correct the pressure and send me on my way. No issues since with the tires, but still no increase in MPG.

I decided to fill my tank and reset the MPG thinking maybe that would do it. I'm now barely at 32mpg and have done almost all highway driving...I previously was around 36mpg for the same driving pattern. Any thoughts on what can be going on? I find it odd that I had no issues prior to the oil change. Thanks!

~ Christie

 

[david5525]

Tire pressure does play a part in rolling resistence which can effect mpg but I wouldn't think it would account for that much difference. I only get 30 average with my 2.0 auto at50/50 city/highway and I keep my tires a couple psi higher than recomended. The higher pressure helps me get maybe a mile or two mpg at most.

Has your local fuel changed with ethonal for winter months? Ethonal has a lower btu therefore makes less power and less mpg.

 

[david5525]

Oh by the way, Welcome to the forumZ from the PNW aka WA. Post up an intro in the Newbie Check In.

 

[tygercsw]

Thanks for the reply!

I would normally think the winter fuel change would cause the mpg drop (don't think they have done that quite yet here in WI - probably in next few weeks). But in this case I literally pulled into Firestone with my display showing 34mpg. I left 30 minutes later with a fresh oil change and when I turned the car on it read 29mpg. Just like that. And it seems to be a struggle to get the mpg near the previous average of 34-35mpg since. It's just odd and I cannot figure out what possibly could have occurred in the bay that would cause the extreme drop.

 

[david5525]

Your right that is just odd. Let me throw another thought at you. Do you reset your mpg every time you fill up? Or do you let it roll on and on? Is it possible they reset it on you when they went through the process of clearing the service indicator for oil changes? If so it may take a while to get the average back up to what you are used to.

I don't know, just throwing out ideas. You have the aero? Does it have the 1.4L? Haven't really heard anyone getting much better than 33-34mpg with the 2.0. I try to drive conservatively and still only average 30mpg but I don't have a lot of highway either.

 

[tygercsw]

I do reset every time I fill up. I thought about them resetting the MPG but it should have read "0" when I started up then. And since then I have reset and still am shy of what I was getting each fill.

Yes, I do have the Dodge Dart Aero 1.4L Turbo. I was getting closer to 35-36mpg prior to the oil change. It's only 2-3mpg but it is bothering me that I can't figure out why it happened.

I appreciate all of your thoughts on this! I have the K&N air filter on my Xmas list so that should help a little, too.

 

[david5525]

I haven't done anything for performance yet. I know some on here have done CAIs and exhaust. Both will help mpg some. I'm happy with the performance I am getting so I was going to go after the sound system next.

 

[jkelly16]

If you had it done at the dealer asked them if they flashed the pcm for any updates. That could cause a sudden change depending on what may have been changed. Don't know, just shooting into the darkness........

 

[tygercsw]

I had it done at a Firestone, but that is still good info to know in case it happens again and I went to the dealer. Thanks!

 

[tygercsw]

david5525 - My family use to own a car stereo business, so I completely understand the sound system part! I'm going to fit my drop-in Kicker Solo-Baric into the trunk next.