01 Maxima 3.0L.. have no check engine light and everything seems to be running good. But lately seems my Max is using more gas that usual. Tire pressures are good and intake system looks to be running good as well. Use mid-grade fuel as well (for as long as I can remember and never had any problems). Also replaced the fuel filter (in the tank) like 2 yrs ago as well as my plugs around the same time. Any ideas out there?

 

So, what's your MPG's for comparison, or is this a hunch you have?

 

more of "eye-balling" the gauge. Losing a quarter of a tank after 25-30 miles driving seems a bit much. Will do more a test when i make a trip at the end of the month.

not too sure if i should be concerned of something more serious. Anyone else out there has had this issue??

 

Fill tank, record mileage.
Drive until just about empty.
Fill tank, record mileage and gallons used.

Do some math and report your results back.
Until then, one can assume nothing is wrong.

 

oxygen sensors check your sensors they get messed up without throwing a code.