Too high mileage

Brake drag is the only problem that can cause fuel consumption increase of more than 1l/100km without fault code and fault light. So if you don’t have any fault lights on check for brake drag. If you don’t have brake drag then it’s likely that it’s just your driving style that’s wrong.

I was already eco driver or hypermiler with my old (normal manual transmission) car. But when I bought my Prius I did get pretty bad fuel consumption figures with it. Actually I got better figures when I stopped trying. Later I have learned how to hypermile a Prius. It’s a lot different than normal manual transmission car. Now I get 3.5l/100km (67MPG) to 4.0l/100km (59MPG) in summer and 4.0l/100km (59MPG) to 5.6l/100km (42MPG) in winter with temperatures down to -32c (-26F). All actual numbers calculated from fill-ups.

My method of testing for brake drag:
Drive something like 10km or 6miles without touching the brake pedal and then stopping without brake pedal (In a Prius you can use B to slow down and then reverse to stop completely). Brakes should be cool. But test the rim then the caliber and only then the disk to avoid burning yourself.

You did convert the fuel consumption to UK MPG. Most of people here are from US so they wount think the numbers are that bad because they think of US MPG. Also the title is misleading high fuel mileage means low consumption.

 

when I first got my prius consumption was 7L regardless of driving style, the trip meter had not been reset for about 40,000k.

I reset the trip/consumption meter one day and its been sitting around 4.4L ever since.

 

welcome to priuschat! how many miles/km on her?
there is a sticky under the gen 2 forums about gas mileage, with a lot of questions that would be helpful if you answer. all the best!

 

Here is the main questionnaire that helps us in troubleshooting your MPG, though it doesn't include brake drag or check engine lights:
Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new | PriusChat

For new owners, see also these threads:
New owner? Want MPG help? Read this first. | PriusChat
Why Mileage Gets Worse in the Winter | PriusChat

 

thanks for the link!

 

Short trips like that where the car doesn't get warmed up all the way and run for a while will really lower your gas mileage. When I have to use the car like that here my gas mileage will be under 35 miles per gallon. When my wife then takes it to work (80 km each way) she gets over 45 miles per gallon.

 

Check the live data from the sensor and compare it to the actual measurements from the sensor wires to determine where the fault is. Best scan tool for a Prius is a computer with Techstream software. You can get it cheaply as Mini-VCI.

 

Did you replace the oxygen sensor which is downstream from the catalytic converter?

Are you using the correct Toyota part?

P0138 means that the voltage from the sensor is higher than the engine ECU expects it to be.