Advice: 2009 Averaging 8.5 MPG (2 Viewers)

[Griffinstrings]

Hi, Recently picked up a 09 with 254k. I'm currently averaging 8.5 mpg on my 5 mile flat daily commute to work. I'm using 87 octane, babying the accelerator, and averaging around 45-50 mph on the commute. Have changed plugs, valve cover gasket, air filter, greased drive shaft, etc. I've ordered new fuel filter. There is a moderate lift and 295/75/17 Grapplers running 40 psi on the vehicle. Other than a possible valley plate issue, the vehicle drives perfectly. Any advice on troubleshooting the mpg would be greatly appreciated. Thanks! Chris in Birmingham, AL

 

[Sandroad]

That sounds about right for a very short commute on very large tires. How are you calculating mpg? If you’re doing it with no correction for large tire size, it will come out low. If you want to take further action (that I doubt will help much), see what others think about a new PCV valve, new oxygen sensors, or mass air flow sensor cleaning.

 

[Griffinstrings]

Thanks for response! I'm referencing the digital readout since last fill up. Good idea on the PCV valve.

 

[AZLX570]

250k+ miles, 34"+ aggressive(ish) tires, lifted, and under highway speeds? I'd calculate it by hand furst but ~10mpg doesn't seem too far out of the norm if that 5 miles is stop and go traffic. At under 5 miles it's probably barely getting up to operating temperature.

 

[Griffinstrings]

Thanks! I think mentally double digits are acceptable and single are not!