Gas Milage WAY too low.

[Blank-Disk]

Gas Milage WAY too low. STUMPED

Recently my gas milage has been pretty lousy at about 15mpg. Yesterday I filled the tank, and hit the trip button. The car sounds and moves normally, but sometimes I notice a little lag, or over reving. Today I went out to get some lunch and discovered that in 21 miles I had lost quarter of a tank. That's about 5mpg. What the ****?! The fuel pump isn't making any noise, and it just passed the emissions test not 1 month ago, and with "flying colors". There's no wet spots in my usual parking spot to indicate a leak. I don't smell any over burning of gas, the exhaust is clean. So wat the ****? My first thought is an 02 sensor, but good god 5MPG??? Any thoughts?

 

[Rob94]

Is it possible that your fuel gauge is inaccurate?? Seeing as you passed state emissions, I am hesitant to guess at anything. Have you tried running your codes? If not, I'd suggest running them both KOEO and KOER.

 

[Whelen_Dealer]

Wel lit's possable that some one is sucking the gas out of your tank when your not arround ?

 

[sdpatt]

There is no way to get an accurate mileage estimate from a quarter tank and there is almost no way that the SHO engine could consume 1 gallon for each 5 miles of travel without setting off numerous error codes for seriously rich mixtures.

In frisky going-to-workout-and-work-and-home driving in town, I regulary get only 15-16 mpg. Out on the highway for a full tank of fuel though, she still covers about 24-26 mpg even at my highway speeds.

Run the KOEO and KOER tests just to see if anything unusual pops up. Otherwise, use the measure of your fuel gauge with a doubtful eye. I would consider it suspect.

 

[DHMag]

Recently my gas milage has been pretty lousy at about 15mpg. Yesterday I filled the tank, and hit the trip button. The car sounds and moves normally, but sometimes I notice a little lag, or over reving. Today I went out to get some lunch and discovered that in 21 miles I had lost quarter of a tank. That's about 5mpg. What the ****?! The fuel pump isn't making any noise, and it just passed the emissions test not 1 month ago, and with "flying colors". There's no wet spots in my usual parking spot to indicate a leak. I don't smell any over burning of gas, the exhaust is clean. So wat the ****? My first thought is an 02 sensor, but good god 5MPG??? Any thoughts?

what did the gauge read when you filled it up ? and after filling, how many gallons did you feed into the tank ?