Lacuna in Hybrid Electric Display

[Transpower]

I own a 2008 Mercury Mariner Hybrid AWD. I love the instrumentation but have recently become concerned that something important is missing from the HEV display: power flow to the rear wheels. Over the year that I've had this SUV I've never seen the diagram show power flowing to the rear wheels, even in extreme snow or rain. Does anybody know how this problem can be rectified?

[Donaldo]

Don't worry, it doesn't work on any AWD hybrids (yet). Since Ford's hybrid AWD doesn't have a separate rear electric motor like a Toyota, there isn't any hybrid function related to rear axle power to display.

[Walt]

Yea, I had the same type of comment about my '07 display. :beatdeadhorse:

 

I do understand that the four wheel drive system used by the gas and hybrid Escapes, isn't simply just 'on' and 'off'. It is constantly variable, and that is always given as the reason why there can't be a "4WD Engaged" light on the dash.

 

However, the hybrid power flow diagram is different. It uses arrows who's lines thicken and thin to show the percentage of power actually flowing in any given path. So, there could certainly be an arrow running to the symbol for the rear wheels, and that arrow's thickness could vary in direct proportion to the percentage of "engine" (gas and electric) power being sent to the rear wheels.

 

It would also give us 4WD owners, finally, some warm cozy feeling that the 4WD system is actually working.

[Donaldo]

I do understand that the four wheel drive system used by the gas and hybrid Escapes, isn't simply just 'on' and 'off'. It is constantly variable, and that is always given as the reason why there can't be a "4WD Engaged" light on the dash.

 

However, the hybrid power flow diagram is different. It uses arrows who's lines thicken and thin to show the percentage of power actually flowing in any given path. So, there could certainly be an arrow running to the symbol for the rear wheels, and that arrow's thickness could vary in direct proportion to the percentage of "engine" (gas and electric) power being sent to the rear wheels.

 

I think what you are thinking of is the display to show electric motor assist as well as torque distribution between front/rear axles. I don't know of any AWD systems that display F/R torque distribution, as it happens so fast (small fractions of a second) that your eyes would have difficulty seeing it at all. The electric motor assist can last minutes, so it is easily visible. Which is probably what you were getting at in the first paragraph!

[Walt]

I don't know of any AWD systems that display F/R torque distribution, as it happens so fast (small fractions of a second) that your eyes would have difficulty seeing it at all.

 

Actually, the thickness of the line would be more like the average of the torque split. And I don't think the average changes all that quickly. If you are on a clear, dry, road, the avg would be around 99/1. If you are on a slippery (ice, snow) road, the avg would be around 50/50. In other words, even though the system might be able to change from 50/50 to 99/1 back to 50/50 thousands of times a second, the overall road traction itself would not be changing that fast.

 

Traction control works the same sort of way. The computer is constantly measuring slippage. However, the green "TC Active" light comes on, and stays on long enough for me to see it.