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Discussion Starter #1
For the past few weeks I was doing mostly freeway driving (approx.
70 miles / day ) and was getting about 48 MPG.

This week-end I did mostly surface streets, start & go, many parkings, no
jump-starts or fast accel. and the MPG dropped to around 32 ???? :x

(same gas from same station, same tire pressure, same weight on car)

Any ideas ?
 

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GrnDrvr03 said:
For the past few weeks I was doing mostly freeway driving (approx.
70 miles / day ) and was getting about 48 MPG.

This week-end I did mostly surface streets, start & go, many parkings, no
jump-starts or fast accel. and the MPG dropped to around 32 ???? :x

(same gas from same station, same tire pressure, same weight on car)

Any ideas ?
How much time between each stop?
Many short trips will bring down your
mileage, as the Prius goes through its
warmup period on each start (assuming
the car has had time to cool off at
each stop).

Any chance you left the AC or the
defroster (windshield position) on
your climate control? You wouldn't
notice the impact of their use if
you usually only do highway driving, but
they can be a real bummer if you do
backroad or "city" driving (lots of
stops, speeds under 42MPH). The
engine has to run to power the AC compressor
for either the AC or defrost settings,
meaning that your engine would run for
your comfort rather than turning off
to go into stealth.
 

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Discussion Starter #3
35 MPG --- ouch

I would guess that over the day I parked 5 or 6 times.

Otherwise 'normal' start and stop traffic (0 tp 30 mph)

The weather was warm and did not see the 'green' thermometer on the cluster so I assume that there were no warm up cycles .

The AC WAS On in Auto ( No MAX and the thermostat was a bit left of 76)

Next time I'll use the 'natural' AC and see how it goes.
 

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The "green" thermometer (you mean blue, right?) is not a clear indicator that the Prius is in warm-up mode. When you start the car, wait 10 seconds. If the engine is still running, the AC is off, and the multi-display does not show any energy flow (e.g. from the engine to the batteries), the engine is running solely for the purpose of heating its catalytic converters. If I've driven my car within the last 10-20 minutes, this will be a brief period (1-2 minutes). Full warmup time for me is 4-5 minutes in summer, but as much as 10-15 minutes in the winter (if I'm running the heater).

In your case, I'd guess your AC usage was causing extra running of the engine. This loss of stealth mode (we don't have to put that in quotes anymore, because Toyota has begun using the term! :) ) would have the reported effect. Some have reported that the mpg drop caused by running the AC on the highway is less than the mpg drop caused by driving at highway speeds with the windows open. However, AC usage in city driving causes a very noticeable mpg drop. I suggest switching the AC off and opening the windows or turning up the fan.

For more mpg tips, go to http://www.john1701a.com and click on "Prius Info" and then "Owner Advice".

Douglas (2002 Silver, Wisconsin)
 

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Discussion Starter #5
35 MPG --- ouch

Bluish-Green to be precise :)

Thanks for the info.
 
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