I have 98 4.6L with 85000 miles on it. The last few tanks of gas, I have only been getting around 12 M.P.G. where I used to get anywhere from 15-18. What gives? Most of my driving is done in the city. What do I need to do to get my old M.P.G.'s back. Any help is greatly appreciated.

 

radjks

I assume that you haven't been making alot of speed runs up and down I-27. It sounds like a simple maintenance issue. When was the last time plugs, wires, coil packs, O2 sensors, fuel filter and/or air filter changed???

I assume that you are buying fuel at the same place as always. I also have a '98 4.6 with 45k and a manual tranny and 16-17 is about normal for my heavy foot with my modifications.

 

You didn't say if it is a 2WD or 4WD...my 98 5.4 4WD is averaging 14.8mpg. I have kept mileage records from when the truck was new. Currently it is averaging about 13.5-14.9 mpg per tank. It depends on how heavy my foot is. I have found that my mileage goes down during the winter months when I average 12.3-13 mpg.

 

If you haven't changed your plugs and wires I'd start there before going all out and doing the coil packs and O2 sensors... A drop in gas milage is a pretty good indicator the plugs need changed.