Severe loss of gas MPG

[TexasShelby]

Any of you had this happen or might know of what could be causing the problem?

In the last 3 months my city mileage has gone from 13.4 down to 9-10. No differences in driving.

Plugs about 10k, filter about 3k. Oil about 2k.

No codes, runs smooth.

I'm thinking perhaps a sensor? Mine is original 07.

 

[ZeroSVT]

Are you relying on the gauge or pen and paper method?

 

[TexasShelby]

little of both actually. I'm pretty sure the computer is correct as I just put in 14.7 gallons on a tank with 4 miles left.

 

[me32]

How many miles on the car?

 

[TexasShelby]

42k

 

[me32]

42k

I'd pull the plugs an check them. Also its says you replaced the filter. Is that the oil filter, air filter or fuel filter? If you havent change the fuel filter i would do that for sure and also your air filter