Need a quick answer, please! At the dealership now.

If the car is idling for any length of time Avg A or Avg B mpg will show low especially if the mpg was reset. I often reset one of the two mpg averages manually every time I fill up. You hold the Trip button down while on one of the averages to reset. Even then you need to drive a few miles to get any kind of idea as a newly reset average can show very high if you are generally going downhill, coasting or going slow. It may show low after reset because of idling, acceleration or uphills. Could be someone pressing buttons reset one of them and the other may still be longer term.

 

It should also show how many miles were driven to get that average. The less miles driven, the more inaccurate it is. Although I can't remember ever seeing something as low as 28, I have seen low 30's at the very beginning of an average. It depends on what you are doing. At a dealership I can certainly see a car driven very little, that may never escape the warm-up phase where the engine runs a lot. I can see drivers 'punching it' to see what kind of acceleration the car has. I can also see a car that is turned on, idled, and then turned off (for 0 miles added, maybe just to demonstrate the electronics). So really hard to say much, unless there are a lot of miles in that average. And even then, as it is at a dealership with all the above complications.

 

The displayed average MPG in the 2015 v will differ depending on which mode the odometer display is in. In trip mode it shows the trip ave. In odometer mode it shows the total average since the last memory reset. There are 2 trip meters, and so a total of 3 different possible averages to be displayed. So the 28mpg figure means nothing without context.

(The memory reset takes place in the energy screen where it shows the big green bars with dates. The past 5 resets will be displayed.)

 

28 mpg for your short test drive only (~3 miles)? No problem.

28 mpg over 3000 miles? Walk away.

 

Fuelly.com will show you the range of MPG of any car you are thinking about. Most v's get in the 40-44 range but there are obviously outliers on the bell curve of those reporting. Many of the displayed figures on dealers lot cars are the result of abnormal use like many test drives involving many starts, warm ups, HVAC on full, short trips, idling, etc. Set the display to read instantaneous MPG and see if it varies from 99.9 down to maybe 20.

 

sorry i was unavailable yesterday.

 

Here in AZ during non summer or winter, I easily get 48 to 52. In mid summer it could drop to 36. And this is in ECO mode.

 

Hopefully the op is not still sitting at the dealer since June. Changing the 12v battery or just disconnecting it will reset longterm and trip mpg averages.