[Peter123]

I own a 2013 Dart Raylee. The MPG indicated by the trip computer has been as much as 40% higher than when I compute the MPG the old fashion way after filling the tank. My wife owns a 2013 Honda CR-V with a trip computer that is never more than a few tenths of an MPG different from computing it yourself. I took the car to the dealer where I purchased it to have the trip computer fixed. The first thing that happened was I got quized about using it properly, did I always delete the past miles traveled, did I delete the past computed MPG, did I restart the MPG computation before filling the tank, did I fill the tank the same way all the time, etc. The dealer could not tell me what the expected accuracy of the trip computer is supposed to be. After about 30 minutes of discussion they finally agreed to keep the car and see what they could do. When I got the car back they had loaded upgraded code for transmission control and for the trip computer. Since the new code download the overall MPG is about 20% lower than prior to the new transmission code upgrade and the computed MPG compared to the self calculated MPG is about 2x as much in error on average. Has anyothre Dart owner experienced this problem with the trip computer in their Dart? I'm getting ready to get rid of the DART and get a small AWD SUV.

 

[david5525]

Yeah Peter,I here you. I started a thread awhile back on what mpg are you getting and how accurate the displayed mpg average is. Mine isn't as bad as yours. I tracked mine for several tanks and found that the displayed mpg overstated the true calculated mpg by 2-3 mpg on every tank full. I get a displayed of 30-32 but the math says 28-29. Don't know what to tell you. My 02 neon used to average 33. But I'm not complaining cause my dart is a hell of a lot nicer.

 

[jkelly16]

I've never seen a car that the computer estimate was accurate. I always do the math.

 

[TXhypno]

My question would be "How does the onboard computer determine mpg?" How does it determine how much gasoline I have used and how much is left in the tank? Mine seems to be very close to the calculated value.

 

[david5525]

Its probably some crazy formula figured out by someone that makes a lot of money. It probably looks at fuel level wich your gas gage displays, then works with Throttle position, What gear your in, Engine RPM and Travel speed from your speedometer.

Do we really need to know all that? Simple devision at the pump gets us a really accurate average MPG.

I guess it gives us something to talk about.

Whats next? If we don't keep our averages up they send out the Environment police?


Just kidding!!

 

[TXhypno]

I always calculate it, was just asking since it seems to me it would be more blind luck than anything else for the indicator to be accurate. That being said, mine is pretty close to what I calculate. Of course, that depends on the odometer being accurate. Used to use the GPS for mileage but noticed the built in one does not offer trip info. Unless I just have not found it.

 

[bones007]

Agreed, I always calculate the MPG myself. my computer is off by a couple miles, always reads better than real calculation. I think Mfg set it up to give you the impression that your mileage is great.... years ago( 60's and 70's) they used to set your speedo to read about 5 mph higher thus making it appear you were getting better mileage , who knows they may still do that as well?

 

[Excoastie]

I'm not sure if it's a factor or not, but I noticed yesterday that the "average" mpg listed is since it was last reset (in my car with ~150 miles on the clock it's never been reset). When I did some scrolling in the EVIC (is it still called the EVIC on the Dart? LOL) I saw that the MPG for the trip odometer was almost 2 mpg less than the displayed average.

I am yet to fill the car up, so I'm not sure what mine is getting, though based on the ~15 gallon tank, ~145 miles on the trip odometer, and the almost three quarters full gas gauge... I'm guessing it's somewhere around 25-26 mpg.

Exco