Really bad gas mileage on 07

How are you measuring your gas mileage? From the Prius screen or by calculating how much you fill up? Though this may not be very pertinent, I've noticed that the screen shows poorer MPG when one stops in traffic, despite the fact that the engine stops. I believe that the Prius is using a simple algorithm for calculating MPG and it cannot be trusted in some driving situations.

I do agree with earlier posts that ethanol and additives decrease fuel consumption, as well as terrain, cold, AC/heater use, and headwinds, though their contributions are difficult to isolate and determine. I can say that my Prius' fuel consumption is drastically lower (more than two times lower) than for my previous '98 Subaru Forester though, and the Forester was not too bad. I hope that your Prius is not a lemon and that you are getting better mileage than your Subaru.

 

OK ...Here's how to check ....Warm up the car by driving it around for 15 minutes....hit reset on your mileage display ........than drive with a mix of city/hiway for 15 miles ..then read your mileage ....it should be upper 30's to low, low 40's ....in 20 degree weather ...LESS if colder ..That will let you know if your low MPG's are a car problem or cold weather problem...winter gas is a part too....I live in Idaho ,and when cold comes ,all mileage in any car goes way down .It will break in to at /about 10,000 miles ..AHHH yes,.........summer is grand.....

 

Come to California, and spend 10 hours a week on LA Freeways at 70-75 mph, and you'll get 45-50 mpgs no problem, and you won't even need the snow tires . It works for me.

P.S. On the same commute my '00 Impreza gets about 26. Its not that hard to beat Subaru mpgs!

 

You have a big advantage living in the warm region of the country. My Prius still gets 48 mpg even with this cold weather we are having. I try to keep my speed below 70 mph on the interstates and try to anticipate stops and follow all the tips that I learned in this forum. For the most part, it is working.

 

it is not easy to beat 30 mpg during these times of cold weather, snowy roads, all of which REQUIRE the use of the defroster/heater running consistantly to avoid fogged up windows.

 

Not true. The Prius calculates mileage by measuring the fuel injection pulses for fuel volume and dividing that into miles driven. If you see your mileage dropping while sitting still your engine is still running and consuming gas. Remember that the Prius has no "engine running" indicator. The only way you can tell if the engine is running is to feel it, which is often hard to do. The energy arrows on the screen show the flow of energy, not engine operation. There are several situations where the engine will idle without producing energy flow on the screen. Usually when it does this it is making heat.

The MFD mileage is very precise and fairly accurate. Most owners report it to be within one or two percent of long term calculations, and usually on the optimistic side.

Tom