Battery power getting low mpg

I wonder why you would expect to get 100 MPG? Isn't it rated at 50 MPG?

 

If the ICE is running then your MPG reading may still be lower even if you're in the EV zone.

 

When the power bar is below the midpoint, it is possible for the engine to stop and the car will run on the battery. When this happens, there will be an 'EV' next to 'ECO' above the bar, and the mileage indicator will go to maximum. Once the car has warmed up-usually a 5 minute (or so) process- and the battery has enough charge- generally 3 bars or more- the car will go into this EV mode when the power bar is below midpoint. This is mode is also called gliding. However, it is possible for the engine to run while the power bar is below midpoint (for a variety of reasons) and the indicated mpg's will be as you noted. With some experience, you will be able to control (somewhat) the several modes available.

Note: do not confuse the EV mode on the system indicator with the EV mode available when you push the EV button on the console.

 

Instead of 'glide', just shift into "N" and coast. It is a lot easier with one caution. If you coast and the vehicle speed climbs over 42 mph, do a one second shift into "D" and back to "N" as a precaution.

The older Prius had an MG1 rpm limit above the 42 mph and would increase the engine idle speed to prevent over-rev of MG1. But testing last week up to 74 mph did not show this still happening with the 2010 Prius. Just I'm a cautious sort of engineer and until we can get a good mapping of what is going on, recommend coasting in "N" above 42 mph with the engine running.

Bob Wilson

 

Gen 3 has a second planetary gearset for M/G2, this makes it MUCH harder to over-rev M/G1.
Hybrid Synergy Drive - Wikipedia, the free encyclopedia
the diagram marked Prius matches Gens 1 & 2, the diagram marked RX400h more closely resembles Gen 3, PIP, v, and c.

 

Hi Puppychew,
Yes, You are correct. the 2010 does not have an EV light to indicate that the ICE is off like the newer Gen3's. You really need a ScanGauge to see RPM and really know what is happening.

Thanks,
Dan