getting 21mpg

We have a survey to fill out, but I think you want do a test drive where you warm the car up about 10-15 min and get somewhere you can do 50-55 MPH level for 10 minutes or so ...you want to see the MPG bars in the display get to around 50 MPG at 50 MPH, maybe 45 MPG in the cold. Maybe get a pic of the display at that point. The display holds 30 minutes of MPG bars.

As low as 20 is pretty bad all I can think is bad hybrid battery or something, but its hard to say.

 

Is most of your driving in heavy traffic jams for short distances? I had a trip today where I was probably around that MPG number - it took 45 minutes to drive 3 and a half miles! But if you've got any amounts of driving where you can get up to 40 miles an hour or more for a few minutes at a time, you should be better than that. Most of my trips to the grocery store (less than 5 minutes driving, 35 miles per hour speed limit, 5-25 degrees F) end up around 25 MPG if it's from a cold start, but anything longer is typically 40 MPG or more (35 MPG when below 0 degrees F)

The engine comes on almost immediately in cold weather for me. On Sunday, when it was 9 below zero, it was going like gangbusters trying to get the car up to highway speed. In my limited experience with above freezing weather so far (only had the car a few weeks now), the engine on my car doesn't start until the car goes above 10 MPH or so from a stop.

 

Hmmm... In that case I'd agree that something seems off. According to Fuelly, the lowest MPG reported for a full tank of gasoline on a 2006 Prius was 31 (when outliers were removed). So if you're getting lower than that for a significant number of miles, there's likely a problem.

If you switch to the "energy" view where it shows the battery level, does the battery level go up and down quickly between 2 bars and 7 bars? And what's the battery level when you first get into the car in the morning?

If the battery level is low (2 bars) in the morning and/or goes up and down between 2 and 7 bars while you're driving, your traction battery might be going bad. If the battery level is steady (typically between 5-7 bars), then it's something else.

 

Sounds like hybrid battery is in good condition. You really need to test your MPG on highway.

 

congrats and welcome! how many miles on her?

 

Based on what you've said so far, your car is running and the battery is healthy. If there was a problem with the electric motor, your car wouldn't move. I'm sure that's fine.

It would be useful to get an idea of your highway miles per gallon just to see what your car does when there are no stoplights and it can go for 10-15 minutes or more at consistent highway speeds. The difference between your city and highway MPG can show if your low MPG is from your commute or something is wrong with the car.

 

This sounds like an odd highway drive that would not result in optimal mpg-- up to 90 mph and mostly between 30-50?! Are you driving in deep snow? Hopefully not at 90 mph. I can not imagine any other way to get 21 mpg unless you are making most short trips of less than a mile. We have almost 230,000 miles on our '04 and the worst tank we ever had was in the upper 30's.

 

Extremely low tire pressure could also be an issue.

 

The first step is always to check the 12v battery, by the way.
There are guidelines posted here to test.
There are also MPG guidelines/survey. We need to know tires etc.
Its hard to say much on the first partial tank.
Unless there is a serious issue you may need a couple tanks for the system to calibrate itself if power was cut off. Hope you are in USA units not metric kpl.

 

In addition to low tire pressure, things like a dirty engine air filter, poorly performing spark plugs, or clogs in the fuel system could affect your fuel economy. Don't know if the Toyota dealer would include looking at that stuff in their System Health Check, but I'd guess so.

 

When you were doing the test drive, what's the highest MPG the consumption graph showed for a 5-minute period? Typically, if I'm driving for an hour on the highway, my consumption graph will show 40s or low 50s unless the temperature is below 0° F.

 

The numbers on the Energy screen (the one with the engines, wheels, arrows, and battery level) are "instantaneous MPG" or supposedly the miles per gallon you're getting at that moment. While it can give indications, what really matters is the average miles per gallon. On the Consumption screen, it shows your MPG average for each 5-minute section of your drive. Typically, the first 5 minutes of a drive from a cold start will be 25 MPG or lower and then the next 5-minute section and the rest will show in the 30s, 40s or 50s depending on conditions. The only time when I've seen a trip of longer than 10 minutes have MPG stay or repeatedly go back under 25 MPG was when I got stuck in big traffic jams.