Can't get it to read over 38mpg avg.

I see what you're saying, but I don't see how that's different from MikeFocke's suggestion to leave the heater off until the engine has warmed up other than not having to remember to turn it on.

 

I thought about something else. In the summer time when the ac is on, the compressor & fans are also running. That puts a load on the battery, thus causing the engine to run more often so the alternator can keep the battery charged. And, if I remember correctly, that also causes more fuel consumtion. Yet the summer mpgs are still better than winter (But in my case, not by much). Maybe it has to do with the summer season being shorter than the winter season.

Bottom line: I am very disappointed with the mileage. The epa says this car should get 60 in the city & 51 hwy. My city/highway driving schedule is typically 50/50. So shouldn't I be averaging 55-56 mpg?! I found out that the epa later revised the mileage for my 07 Prius to: c 48/h45. Big difference!

 

I'm sure this has been discussed several places -- but here are some factors to think about -

One, the AC uses electricity yes, however - the 5 minutes you may be at a long red light - is nothing to the capacity of the high voltage battery - remember, the 12v battery only runs the computer self check, dome lights, and after you hit the start button and the relays lock in the traction battery - EVERYTHING runs off the traction battery. so in the summer - by the time you start driving again - and as you say 50/50 driving - once your above 10mph on acceleration when the gas motor kicks in to supplement acceleration and higher speed driving - you're charging anyway ... regardless. so you regain what you just lost at the light.

in the winter - a couple factors come into play - mainly the temperature (obviously) and also wind. ever notice how much more windy it is in the winter than the summer? the temp plays a factor in that the engine has to stay warm itself, and keep the coolant water warm to provide heat for you and your passengers. want to save more, run in eco mode...
or turn your hvac system off at stops - the engine will shut off since there is no demand for warm air. I do this when i pull into the garage especially if the engine is running - that way, the computer shuts the fuel pump off - and kills the engine. if i just hit the stop button - then there is a tad bit of unburned fuel left in the intake, which will potentially cause the dreaded engine knock at start up -

food for thought -

 

[quote="mudmanrv, post: 1744439, member: 84514" EVERYTHING runs off the traction battery"

Not true. Read your manual. All accessories (Radio, wipers, etc) get their voltage from the LI battery.

 

LI ? Did you mean to say "12V Battery".

 

I beg to differ - when the car is not running -- yes. I agree. or in the "accessory" position - however - once the HV relays latch in everything litterally runs off the HV battery - as it supplies power to the inverter and the inverter charge circuit lowers the voltage to 12v and pumps it into the 12v battery to charge it...

You are correct that yes, there are certain items like the parking lights, radio, etc. that are on the 12v circuit - not arguing that. but - once you hit the power button - and the big battery comes online after the computer self check -
then all power comes from the big bat - and it charges the 12v bat. much like on a regular gas car -- the 12 volt battery starts the engine - but once the alternator is spinning - your power is coming from it - as you consume more than what the battery can sustain by itself.

 

So how is your mileage now? Has it improved?

 

I haven't exhaustively read the thread (all two pages, lazy ), but some ideas:

1. What are your ambient temp's like? Setting the cabin temperature a little lower will much increase the likelyhood of engine shut-off at red lights and such. It doesn't have to be off, just lowered. I find with our reg Prius I can get the engine to turn on/off somewhere around 20~21 C. And leaving it around 19 doesn't make a big impact in the comfort level, keeps the fan speed low if it's on Auto, and so on.

2. Check your tire pressures.

3. Block heater? Toyota offers them. Not cheap installed, but worth it. About 2 hours use needed to level out.

4. Grill block? This is cheap. Likely the plumbing pipe insulation tubes will work. You'll need to research how much, at what temps, what zones, etcetera.

5. Last but not least, driving efficiently, which is something you can always improve on.

 

Don't think so. The 12 volt powers the car's computer, but turning over the engine is very likely powered by the hybrid battery and the electric motors. No conventional starter involved.

 

The difference is that using the auto fan setting will command the engine to continue running even if it would stop with the heat off.

 

Sorry. I did mean to say 12 volt.

 

I was referring to a regular gas car there... where its 12v bat starts the engine - but then after it's running - it's alternator powers nearly all the accessories - since nowadays, there is no way a conventional battery could sustain that much output.

 

i've noticed the heater/ac makes a significant difference for my 2010 prius. the GF loves the ac/heater though.

 

Trust me, the GF is more important than a few MPGs.

 

I leave auto climate control and AC on all the time, temperature set anywhere from 70-75 for comfort. I set on the lower end when the sun is shining directly on me and on the high end on a cool morning with the seat heaters on as well. The last tank I just filled up returned 39 mpg 90% city driving around Vancouver. Average low 36f, avg high 50f.
AC operates often on rainy days for humidity control and the odd warm sunny day the past couple weeks on this tank.
My previous car(Honda Fit) would struggle to achieve 28mpg in these conditions.