flagshipone

2013 Acura RDX
recently the range indicator has been jumping all over the map as far as "miles to empty" After filling up it will jump from 420 miles down to 350, back up to 420, etc. The fuel gauge seems to be reading the correct amount of gas all the time. I am think its a bad sensor of some kind but there is no Acura dealership with two hours of me to verify so I am hoping to do a bit of self-diagnosis. any input?

thoiboi

Range indicator is variable and based on your current driving dynamics so it may change. Don't fret it.

RDX-Rick

The range value is calculated by using the average MPG over the last 20 miles( my best guess), and the current amount of fuel in the tank. Because range is calculated based on the average fuel consumption over the last 20 miles, it is normal for it to rise and fall as you drive under different conditions.

For example lets assume you have 5 gallons of gas remaining in the the tank.......

if you have been driving on the highway for more than 20 miles, and your average consumption has been 25 MPG, then your range is 25mpg*5G =125 miles.

After getting off the highway, and driving through town, where your fuel economy is 15MPG, your average economy for the last 20 miles is
(19*25+1*15)/20 or 24.5mpg
and your range is 24.5mpg*5G= 122.5 miles

After driving 10 miles in town at 15MPG, your average fule economy for the last 20 miles is....
(10*25+10*15)/20 or 20MPG
and your range is 20mpg*5G = 100 miles

After driving in the city for over 20 miles, your average fuel economy will be 15MPG and your range will be 15MPG*5G = 75 miles.

Of course the opposite will happen if you have been driving in the city for more than 20 miles, and then get on the highway for 20 miles. You would see the range gradually increase from 75 miles, up to 125 miles as you drive further. At that point, even though you remain on the highway, the range estimate will start to drop again as you consume the gas remaining in the tank.

These changes in range, normally happen slowly over a period of miles. Since you used the term "jump", it may be that you are talking about something different than this normal rise and fall. If you are really seeing the range estimate jumping up and down within seconds, then that is not normal. Since range is calculated from your average MPG, did you check to see if that value is also "jumping" up and down.