So I recently just bought my first car and first jeep and for some reason my fuel economy has been awful. I checked my trip computer and I'm getting 9.5 MPG... I have about 83500 miles on it wondering what I could do to fix it. I've been looking around and people are saying things from new spark plugs, O2 sensors, throttle body cleaner, and new spark plug wires. Any help would be great.
Do you know any of the maintenance history? If not, I recommend picking a service interval from the owner's manual and doing everything to get it back to acceptable performance. For instance, use 60K miles to do the following:
- spark plugs
- PCV valve
- xmission fluid & filter(s)
- fluid change in xfer case & both axles
- new serpentine belt
- air intake filter
- EGR valve (optional)
- spark plug wires (optional)
Now you are starting from a position of knowledge.
- When performing normal tire rotations, inspect brake shoes and make sure that the brake pads are not dragging.
- Go to Advance Auto (or equiv) and borrow their code reader. See if there are any active or pending DTC's that you need to pay attention to. Hidden O2 sensor DTC's will adversely affect your mpg's.
Do these things after you check your tire pressures.
BTW: I run mine at 34.5 psig cold. Door sticker says 33 psig and tire dealer puts them at 37 psig (I have no idea why) and the ride is uncomfortable at that level.
As a point of comparison, I get 14.5 mpg around town and 18.5 mpg in the 5.7L HEMI.
Hope this helps somewhat. CAUTION
: This advice may be worth what you paid to get it!