Typically I'm getting 48 to 49.5 MPG per tank. To get this I need to stick the the freeway speeds and not cruise above 65 MPH. I'm very happy with this performance.
Normally I'm gentle on the gas but for one or two tanks I've tried deliberately accelerated hard from most starts. At most this only dropped my efficiency by about 1 MPG.
A colleague at work also has the 2004 Prius but is only getting about 43 MPG. I think that the difference in elevation between his home and work is killing his efficiency.
I did a quick back-of-the-envelope on the batteries. The NiMH cells are 6.6 A-Hr at 201.6 V total, which is 1.33 kW-Hr. The car weighs 2890 lbs or 1,300 kg. The Prius charge control typically only cycles the batteries up or down by about 25% from the 75% capacity set point (if I can believe the battery level indicator). This means that the battery will typically only store enough energy to deal with an altitude change of about 92 metres, or 300 feet. Go outside this limit and you're outside the regenerative capacity of the system to "level out" the road.
I guess the moral here is that the Prius is well optimized for typical driving. Hard acceleration doesn't seem to be a problem, but driving above 65 MPH or long climbs will knock the efficiency down fairly quickly.
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Typically I'm getting 48 to 49.5 MPG per tank. To get this I need to stick the the freeway speeds and not cruise above 65 MPH. I'm very happy with this performance.
Normally I'm gentle on the gas but for one or two tanks I've tried deliberately accelerated hard from most starts. At most this only dropped my efficiency by about 1 MPG.
A colleague at work also has the 2004 Prius but is only getting about 43 MPG. I think that the difference in elevation between his home and work is killing his efficiency.
I did a quick back-of-the-envelope on the batteries. The NiMH cells are 6.6 A-Hr at 201.6 V total, which is 1.33 kW-Hr. The car weighs 2890 lbs or 1,300 kg. The Prius charge control typically only cycles the batteries up or down by about 25% from the 75% capacity set point (if I can believe the battery level indicator). This means that the battery will typically only store enough energy to deal with an altitude change of about 92 metres, or 300 feet. Go outside this limit and you're outside the regenerative capacity of the system to "level out" the road.
I guess the moral here is that the Prius is well optimized for typical driving. Hard acceleration doesn't seem to be a problem, but driving above 65 MPH or long climbs will knock the efficiency down fairly quickly.