New used Prius 2010

That's actually horrible a bad running 2009 gets 37 to 39 mi to the gallon so whatever this generation 3 is doing is not happening That's like 30 mi to the gallon 32 or something I don't even know I can't remember what your tank holds and what you're fill interval is. Our generation 3 there two of them here generally sat around 47 mi to the gallon most of the time on the display.

 

Congrats and welcome!

how many miles on her?

300 miles is excellent if you refill with 5-6 gallons.
If you refill with 10-12 gallon’s then it is quite poor.
There are many things you can do to improve fuel economy, do you know the service history?

 

I think on Fuelly.com, you will see that 44-45 mpg is about average for a 2010 Prius. But fuel economy is affected by a lot of factors.