Poor gas milleage

1) Inflate the rear tires to 40 psi and the front tires to 42 psi.
2) Stick with regular gas. The Prius calibrates fuel mixture optimizations over time and changing octane hurts more than helps. The engine is optimized for regular.
3) Check the oil level and make sure the oil is at or below the Full line. Very easy, but very important check.
4) The first few tanks of gas are not going to give really good mileage since the engine is wearing in and the Engine Control Computer is slowly optimizing the engine mixtures.
5) Check actual mileage at every fill up using the trip meter and the amount of gas filled. Need to see how far off the MFD is compared to actual data.
6) Ensure that the battery vent at the back right elbow of the right rear passenger is not blocked.

Truly your driving technique is everything. jack rabbit starts and hard breaking will decrease your mileage considerably. check out our "club links" on the website below and you'll find some techniques to help.

keep at it, you'll get it as soon as you can understand the workings of the HSD.

http://clubofprii.org

Not to burst your bubble, but I drive my prius like it were an indy car. No gentle braking, easy on the accelerator, no coasting to the stop lights. And...I routinely get 50+ mpg, usually in the range of 50-53. And my daily commute is 20 miles, in both stop and go and highway traffic. Nothing special.

Try this, turn the fan on your climate controls down to it's lowest setting. Set the inside temp to 73-75deg. And see what you're mileage goes up to. I've been driving mine for almost 3 years, and have found the fan to be the single biggest factor in mpg in the summer. I'm still working on a strategy for winter, and am close to achieving 50+ as well. Oh, and inflate the tires to 40 psi.

The EPA (not Toyota) has changed the expected gas mileage for a Prius down to 46 mpg combined. This is achievable with practice. What you have to practice is relaxed driving. Spend time in the right lane and set the display to show the MPG. Pretty soon you will get the feel for optimum Prius Driving.

I am not one that drives aggressivly, and they are usually not short trips and so far the summer vs the winter has not made a difference in the mileage

Chuck,

The Prius has too many compromises to obtain the promised economies without owners dramatically changing driving habits. Example, do you notice that the car cannot run strictly on the electric motor from a standing position? The electric motor is underpowered and the batteries inadequate. I purchased a 2006 and consistently get better mileage with highway driving. If the electric motor was more powerful this would not happen.

Jim K

Several factors affect mileage in the Prius. Short trips in town of less than 2 miles will give you lousy mileage. Slowly accelerating to speed is just as bad as a "jack-rabbit" start. Accelerate between moderate and lead-foot to get up to speed, trying to coast or slowly decellerate for the majority of the time between stop signs.
Be aware that you will get lousier mileage in the winter than in the summer (the air has more density, and gives more wind resistance, when the temperature is below 55 degrees in most places-wind resistance is the biggest killer of mileage after low tire pressure)