HV MPG Only?

i'll be interesed to find out as well, the pip does not do this calculation, even the it tracks ev/hv miles and gas usage separately.

 

Take a look at page 221 in the user manual.
EV fraction is tricky because it might include time the ICE is off in HV mode but the MPG result should be close.

Example:
Say you drove 200 miles and the MPG display for those miles is 80
EV fraction is 25%

Then 150 HV miles required 20/8 gallons

 

they make you do the math yourself?

 

Nah. You pop the numbers into a spreadsheet on your smartphone.

I'm just kidding --- I don't know if a calculation exists on the display.

 

I doubt this will give you good numbers. My Prius C typically ran about 35-45% in EV mode. In other words, the EV portion of HV driving can be quite high depending out your driving style.

 

Yes ... but then your non-EV MPG will be low

 

This doesn't make sense. There is no "non-EV MPG" since the Prius C is strictly and HV; it has no plug in capability.

 

Your HV has ICE-off and no-combustion-modes, which I *think* the car meter will lump as EV fraction.

Think about it this way: if all the motive force is from the battery, the car does not know if the juice originated from a plug or the ICE. To the extent that the battery juice was from prior ICE use the car will show more gallons burned for the distance traveled and your overall trip MPG will drop accordingly.

The calculation just goes backwards.

 

the car computer can do the same thing as we do manually at the pump. hv miles reported are all we have to go by. how accurate they are is anybody's guess.

 

I'm not really sure what your concern is. If you don't use any gas, then your MPG is infinite. If you you used 1 gallon to go 200 miles, then your MPG is 200.

If you want to know what the MPG is when the car is strictly in Hybrid mode, then switch the car to hybrid mode when you start it up and then drive.

 

Zero your trip computer as soon as EV is depleted. The car will tell you the MPG number for the trip follows.

 

it's early, but it sounds like the prime is just like the pip. unfortunate, if that's the case. but the only option, aside from driving without a wall charge is to measure your fill up, and divide into hv miles driven. i hope i'm wrong, because i thought this simple improvement would be available somewhere in the 3 million prime data screens.

 

True, however since it does know (or at least should know) how much electricity came from charging, for calculation purposes it could use something like a FIFO method and assume that the electricity consumed first is the electricity that came from charging. Then once that "pool" of electricity is used up anything else comes from regen and ICE. In fact since it should know how much electricity came from regen, wouldn't it be nice if after a trip it displayed the following information:

You drove 100 miles, power for those 100 miles came from:

X gallons of gasoline
Y kWh of plug charging
Z kWh of regenerative braking
Z1 kWh of regenerative coasting

Again it would assign an order used for calculation purposes, i.e. plug charging first then regen braking etc. then once those are "used up" any other electricity used is assumed to come from normal HV operation and charge mode, which are already accounted for in the gasoline column.

Any unused plug or regenerative electricity after the trip would be carried over to the next trip.

Edit - I realize this has limits in terms of accuracy, but at least it would give you some idea of what is going on. After all how accurate are the existing MPG and EV values that are displayed? Not perfectly accurate but again at least they give you something to relate to.

 

Reporting EV use ratio on a car without a plug is just flat out stupid. All the energy the car uses comes from gasoline, including the energy that goes into and out of the battery. Knowing how much time was spent on EV propulsion isn't going to help improve the driver's efficient use of the car. It can actually hurt as they try to get a higher EV ratio, only to have the ICE come on and recharge the battery at times it would be inefficient to do so.

The issue is that the MPG number derived that way is misleading since it doesn't account for the energy from the wall. Some Volt owners were jumped on for reporting fuel economy here in the early days of that car.

It would not be difficult for the display to show Hybrid mode mpg or mpge for overall efficiency.

 

It is not for the PiP and I suspect for the Prime as well. Distances when ICE is off in HV mode are not included in EV miles, they are HV miles.

 

Well I don't know if this helps any. But my calculations yielded 31mpg over 900 miles... And that's when the Ice is on. So that's damn good. Ie - that's not the true hv mpg calculation but a pretty true ice only calculation