Help with MPG...Bought Used 2010 prius

First reset the tripometer or fill the tank and start over, then see what you are averaging after three of four days, if you drive it like a normal car you really should get around 43-46. You have to work some for fifty+.

 

The other factor that can make a big difference is the length of your average trip. When the Prius first starts it will run the engine until it warms up. Depending on the temperature this could be anywhere from a minute or two to 5 or 10 minutes, and during this initial warm up time your gas mileage will only be in the 20's or 30's since the engine is running all the time. If you only drive for a few miles then most of your trip will be spent with the engine running to warm up and your fuel economy will be rather low.

 

I think a week is too early to get concerned about mpg. Make sure you have reset both trip/mpg meters since buying the car, to clear out any interference from previous drivers. Then don't do anything special now, just drive 'normally' for a full tank in order to get used to the car and establish a baseline. Working too hard for high mpg at the start can be self defeating, and without a baseline for comparison you don't really know if special driving methods are working or not. It is too easy to do it wrong.

Sometime after the first full tank, post here with your answers to this questionaire: Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new.

Two things you must do right now:

(1) Check your tire pressure. It should be at least 35 psi in front, 33 rear, but no more than the max number molded into the sidewall, when cold in the morning. If measured after driving a few miles or the sun's heat warms the tires, it will be higher. More pressure is better for mpg, but worse for ride comfort.

(2) Check oil level, confirm that it is close to full, but not way over.

Some optional things now, not mandatory yet:

(3) Check battery voltage, making sure it is above 12V in the morning before ignition is first turned on. This is more important with old batteries. Your 2010 is young enough that this is not likely a problem yet. And unlike the older models, your console doesn't have a convenient built-in diagnostic readout, so a separate device is needed to make this check.

(4) Reset one of the trip meters every morning, so that you can watch how MPG changes through the day. It will start out pathetically low, then improve as the car warms up and driving distance increases. Even very slight uphill grades will reduce mpg. The round trip figure at the end of your day is the only one that matters.

Right now, this daily mpg reset will highlight the mpg penalty of engine warmup and short trips. (It is even worse on non-hybrids, but usually hidden by lack of an mpg display.) Later, it will provide rapid feedback about what special driving methods work better than your normal baseline style.