Fuel economy poor - 2001 S40, 250 per tank

[Dan Timberlake]

What is your mpg X 2.

Once I had determined determined that the mpg is indeed low, and that the fuel gage calibration is off, I'd start troubleshooting.
- On many cars if the coolant temp sensor is bad or disconnected the fuel injection CPU will the engine is cold and provide a richer "cold start" mixture all the time.
- Don;t know about S40s, but On RWD Volvos there is a small vacuum line that goes from the intake manifold to the CPR. If that is is disconnected or plugged it will crank up the fuel pressure a bit thinking I'm at full throttle all the time and cause the mixture to richen. Un necessary richness can whack fuel economy noticeably.