Hi, just learning my 2005 package 4 Prius. Got up to almost 50mpg last tank and now the weather has turned cold and the mileage has tanked.

I know the energy display is only updated so often, but it seems to ignore the ICE running many times. Does this mean the ICE is just on to warm up and is not charging the battery?
How often is the dispaly updated? Does it ignore other events?

Thanks in advance, Robert

When the ICE is warming up but not generating power or propelling the vehicle the car does not display a power line to batteries or to the wheels. However your average FE will drop. So the car isn't ignoring anything or not reporting anything.

If you thought short trips in the summer were no good for FE, try this during the winter. Your FE will really suck, but still remains better than what you would get on any other car driven under the same conditions.

It has been said:
Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2.
2005 Prius, Melinium Silver over gray, package 5 (AI)

I've had my Prius II for a year, and I noticed in the warmer weather, I got 52MPG average, and 48MPG in cooler weather. I do about 75 miles/day about half of that is highway, and the other half is 50 miles per hour suburban roads with lots of stoplights. I always use cruise control on the highway, and try to use it on the smaller roads. I always have climate control going. So in the summer time with A/C seems to beat winter time with the heat running.

I've had a surprise in the last 2 months with my 2005 Prius. I purchased it in August, had average mileage of ~55mpg, while commuting 60 miles to/from work each day on a combination of local roads and interstate. But in the last 6 weeks or so (November and into December) something has happened. I'm only getting 40 to 45 mpg.
I'm paying close attention to my foot on the accelerator, how much I use the heat--and I'm paying very close attention to the energy display. I find that the display is confusing; the manual doesn't tell me what the colors mean and what I should do in response--so I feel I'm flying a bit blind in trying to improve the situation. Bottom line: I wonder about the published mileage estimates, and I find the manual to be incomplete in coaching new Prius owners.

Are you sure the ICE is running? Even if you are coasting/electric-only, it spins when over 41(40?)miles per hour to protect the electric motors, but is not necessarily running with fuel flow. A very counterintuitive thing.

Carol- your mpg hits is completely in line with winter. The EPA test is done with summerblend gas and at room temp. Take hearth that your lousy winter mpg is still far better than anyone else's lousy winter mpg.

Howard- there are many other factors conspiring against any sort of heat engine trying to make any sort of movement in the winter- you are right that AC full balst in the summer is not as harsh on FE as plain old winter temps.

Somebody help me here: What is "ICE"??

Internal Combustion Engine - ICE is easier to type.

IMO the display software should be updated to estimate the effects of the ICE running at all times below 41 miles per hour in the MPG display, whether propelling the car or not. This would seem to me to be an easy thing to do and will certainly be more accurate. My own experience is that the display MPG can be off as much as 10% to the high side. I would rather the display MPG to be on the low side rather than the high side any day.

Alden Bowles
2005 Toyota Prius II HSD

Are there software updates that we are supposed to get from Toyota to somehow update the display? Anybody know?

I don't know of any updates specifically addressing this issue. On place to look for information is www.priusonline.com. There is a lot of good information there and a lot of Prius geeks around who may know.

Alden Bowles
2005 Toyota Prius II HSD