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Armando G

AVG / MPG sudden drop

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I have a '15 SXT FWD, well maintained DJ that I have not had any issues in the last 3 years. I usually average 16.7 to 17.3 MPG / AVG on the dash monitor, since I do almost no freeway driving. On long trips I average 24 to 25 mpg, which is pretty satisfactory to me. Over the weekend I got in the car and noticed the display showing 12.9 AVG, which was very surprising to me. I drove about 3+/- miles and it went up to 15.4 AVG. I thought it was just a fluke and by the end of the day I ended up at 16.5 AVG. This morning I got back in and the display showed 12.9 AVG again. I drove to work (about 4 miles), and it ended up at 16.3 AVG. Car sat all day, and at the end of my day (about 8 hours) when I got in to go home, again the display showed 12.9 AVG. I looked around for anything similar on the forum and web, but do not see anything like this. Also not sure why the magical number of 12.9.

 

Anyone experience this before? Anyone know as to why this could be happening, or how to solve it? I'll be filling it up later today and will reset it at that point. I have not used any other gas station other than I normally do (Chevron 89). We have had a pretty big drop in our local temp, but not anything outside of the usual normal yearly drop. Seems like a system type of issue more than anything. No issues with starting the car or noticeable drop in the charging system (battery).

 

Thoughts? 

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first off the readings from the dash can be misleading only real way of tracking mpg is gallons of fuel vs mileage driven and short trip at highway speeds can make a big difference and also idling time while car is warming up. also they way your car is park for instance on a steep driveway overnight and them the tank pressure gets equalized over night,also some elevations on your drive to work  might be more subtle than you know as mostly down hill on way to work and uphill the way home.if it was earlier in the yr could be the station switching over to winter grade of gas from summer gas.... so many possible reasons....or maybe the kids or other half got a little drag racing going on....

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4 hours ago, 2late4u said:

first off the readings from the dash can be misleading only real way of tracking mpg is gallons of fuel vs mileage driven...

 

+1.

 

When I questioned the fuel tank gage level and the mpg readout, the dealer replied that they are estimates only. I find them both to be reliable enough but the mpg can fluctuate depending on all the conditions that 2late4u stated above. The only reliable way to track mileage is the hard math way and being able to compare to past performance. This is not a bad idea in any vehicle from time to time. Then you have a reliable baseline.

 

As the average comes back to normal with driving I would not be concerned, at the moment, and continue to watch it. Do check your tire pressures as winter cold will cause them to drop more than people realize.

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On 12/10/2018 at 7:23 PM, Armando G said:

I have a '15 SXT FWD, well maintained DJ that I have not had any issues in the last 3 years. I usually average 16.7 to 17.3 MPG / AVG on the dash monitor, since I do almost no freeway driving. On long trips I average 24 to 25 mpg, which is pretty satisfactory to me. Over the weekend I got in the car and noticed the display showing 12.9 AVG, which was very surprising to me. I drove about 3+/- miles and it went up to 15.4 AVG. I thought it was just a fluke and by the end of the day I ended up at 16.5 AVG. This morning I got back in and the display showed 12.9 AVG again. I drove to work (about 4 miles), and it ended up at 16.3 AVG. Car sat all day, and at the end of my day (about 8 hours) when I got in to go home, again the display showed 12.9 AVG. I looked around for anything similar on the forum and web, but do not see anything like this. Also not sure why the magical number of 12.9.

 

Anyone experience this before? Anyone know as to why this could be happening, or how to solve it? I'll be filling it up later today and will reset it at that point. I have not used any other gas station other than I normally do (Chevron 89). We have had a pretty big drop in our local temp, but not anything outside of the usual normal yearly drop. Seems like a system type of issue more than anything. No issues with starting the car or noticeable drop in the charging system (battery).

 

Thoughts? 

Hi Armando G,

We understand why this may be concerning. Please let us know if you decide to have your dealer look into this. Just send us a private message and we will happily provide you with an added layer of assistance while your vehicle is at the dealer.
Lydia

Dodge Social Care Specialist 

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4 hours ago, DodgeCares said:

Hi Armando G,

We understand why this may be concerning. Please let us know if you decide to have your dealer look into this. Just send us a private message and we will happily provide you with an added layer of assistance while your vehicle is at the dealer.
Lydia

Dodge Social Care Specialist 

Thank you for the response. I just filled up this morning and reset the system. I will give it a couple of days and see how it goes. If it continues I will get it checked. 

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Calculate mileage the old fashioned way. Don’t rely on the onboard system. Wildly inaccurate. 

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