Fuel Economy Display Quirks

[Sailorman]

I've noticed a few quirks with my fuel economy displays over the last few days. Has anyone had same and is this normal? I've only had the car for a week and still getting used to it. I'm located in Canada so unit settings for display are set to metric.

 

I've noticed the readings in the dash display are not always exactly syncronized with what's showing on the Nav display. Example: the dash display for average fuel consumption is currently showing an average of 6.4 L/100k while the Nav reading for average is showing 6.5 L/100k. I've also noticed when I start the car and ICE come on the instant fuel economy reading goes to the highest point for a few minutes and then settles down. The highest point suggests the car is using 30+ L/100k which can't be right even if the car is warming up. Outside temperature here is 50-60F and the car is garaged.

 

Any feedback would be appreciated.

[EntropyAvatar]

I've also noticed when I start the car and ICE come on the instant fuel economy reading goes to the highest point for a few minutes and then settles down. The highest point suggests the car is using 30+ L/100k which can't be right even if the car is warming up.

 

If you are burning gas but not moving forward, then your litres per 100km is infinite. It doesn't mean that you are burning a huge amount of gas. Similarly, if you are going slow and the engine is running (mostly charging the battery), then your instant fuel economy can be poor.

[SailCar]

The display on my NAV scareen doesn't stay in sync with the dash meters either. The NAV side appears to have a delay in getting or processing the data. ie, it will show ICE activity for a few seconds after it has shutdown.

[lolder]

There are 5 different mpg numbers displayed on the dash.

1) Long Term Fuel Economy displayed in the Trip Summary after each trip (resettable in the set up menu}

2) Avg. Fuel Economy displayed in a left side info screen (resettable by the reset button)

3) Instantaneous mpg on the gauge

4) Fuel Economy for the trip listed in the Trip Summary after shutdown

5) If bar graphs selected, mpg for the intervals selected.

 

These are all different. I am unfamiliar with the Nav displays but they are similar to those above. It is important that you read the threads in this forum in their entirety and also the owners guides several times.

[SailCar]

lolder, There's another instantanious meter available in the HEV menu on the Nav screen. While redundant, the data it shows varies from the one on the dash.

[lolder]

lolder, There's another instantanious meter available in the HEV menu on the Nav screen. While redundant, the data it shows varies from the one on the dash.

Do you think it's different or slightly delayed?

[SailCar]

I watched it this afternoon. As the dash meter "floats", the Nav meter "jumps", and it goes to more extremes than the dash one does. I wasn't sure, but I guess my verdict is that it's different. The dash meter seems to be more accurate.

[Sailorman]

I watched it this afternoon. As the dash meter "floats", the Nav meter "jumps", and it goes to more extremes than the dash one does. I wasn't sure, but I guess my verdict is that it's different. The dash meter seems to be more accurate.

 

I agree .... The intant mileage reported on the NAV is almost useless. My dash meter will show 0 when the car is stopped and running EV and the Nav meter will show 30+ at the same time. When I drive the car it will bounce back down but it seems erratic to me. I've also noticed the average displayed on the NAV will lag the dash display.

 

Does anyone know if it's possible to change the home screen to show the 10 minute interval display in the bottom right half of the home display.

Edited March 19, 2010 by Sailorman

[Sailorman]

I agree .... The intant mileage reported on the NAV is almost useless. My dash meter will show 0 when the car is stopped and running EV and the Nav meter will show 30+ at the same time. When I drive the car it will bounce back down but it seems erratic to me. I've also noticed the average displayed on the NAV will lag the dash display.

 

Does anyone know if it's possible to change the home screen to show the 10 minute interval display in the bottom right half of the home display.

 

I had a closer look at the Nav manual and it looks like the instant fuel consumption inconsistency in metric is supposed to read that way. The manual says that if the units are set to metric, the instant fuel economy meter on the NAV will display 30+ L/100k when the car is stopped, and that it will read "0" L/100k on the dash display. It says the NAV meter will show the correct reading when the car is moving. Guess this is known bug that Ford isn't planning to fix. Not a big deal, but seems a bit silly to have 2 displays returning different results at any time whether it is set to metric or mpg.

 

The other problem that continues is that the results in the NAV display for average fuel consumption lag the dash display; and this lag can be considerable. It's not a few seconds. I've had different readings for average fuel consumption last 30 mins or more. The difference is one tenth. ie. reading 6.3 L/100k on the dash meter and NAV meter reading 6.4 L/100k. I'll have to switch back to mpg and see if there is a lag there too.

Edited March 21, 2010 by Sailorman