We purchased a used 2008 Prius Touring package 5 in December. We have never really seen the mpg we were expecting. Overall the car is in good shape and the only thing I have changed is the spark plugs. I used the iridium plugs that everyone here recommended. The car has averaged 40mpg since we got it. I have adjusted air pressure and adjusting driving styles. Just can't seem to get it to epa standards. Any advice. Thanks.
Two ideas; Just how fast are you driving? If it is mostly 70+ MPH that seems right. Have you checked the voltage of your battery after it sits overnight? Weird stuff happening? MPGs dropping? Test The Battery | PriusChat
Jimbo thanks for the reply. Its my wifes car and she drives about 30 miles round trip each day for work and none of it is interstate. If I had to guess I would say speed average would be 30-40mph. Just your basic side roads here in Charlotte. When I changed the spark plugs I made sure to gap them correctly but I feel like maybe I didnt do it perfectly and that may be hampering the mileage. I might try to do them again and see what the outcome is.
Driving techniques and habits factors greatly for city driving. City mpg can be very high or very low. Try keeping the climate control off instead of in "auto" mode. Use it conservatively, in manual mode, as needed. Anticipate stops and slow-downs to minimize use of the brake pedal. Don't get going too fast before a stop or slow-down. Hang back and glide or use a little regeneration by releasing the go pedal. Use moderate acceleration (rpm ~ 2500 estimated) to get up to speed and then release the pedal to initiate glide and re-apply slight pedal pressure to the point of minimal energy transfer for coasting. Speeds of 42 mph and under are ideal, because the gasoline engine can completely stop. Pulse-and-glide is most effective at these speeds. In very heavy traffic, try to keep speed as constant as possible and use "the electric crawl". "Play the accordion" with the space in front of you to help keep speed constant. It's much more energy efficient than the stop-go-stop typical of congested traffic. If you have had the service department adjust the parking brake, check to make sure it was not adjusted too tight. Good luck!
Great driving tips from tanglefoot. Other things to check on the car itself are: 1. Check that the oil is not overfilled. 2. Check that the 12V battery is in good condition. 3. Check that you have low rolling resistance tires fitted. This is last point seems to be a particular issue with the touring model. Many people want performance tires on their touring model but don't realize that a poor tire choice can result in an immediate loss of 5 MPG or more.
Check alignment. The rolling friction can be increased if it's out. Also brake drag can happen if the slide pins are corroded. The car should coast easily and far. As for plugs, if you used OEM plugs, they don't need to be gapped.
In addition to suggestions already posted, check to see if the tires are LRR (Low Rolling Resistance). Tires can make a big difference in gas mileage.
Keep in mind, most Touring owners do not get the EPA estimates. The bigger tires tend to take away from city mpg.
