I average about 15MPG in the city un-loaded (as my truck is much of the time) on the highway (loaded with a quad and towing a small pop-up trailer) if I keep my foot out of it I can generally average about 18MPG. I'm on stock-sized 235 A/T tires (for now), stock gearing, auto trans 3.0 V6.

I like diesel's as much as anyone (my daily driver is an F-450 with the 6.0 Powerstroke) but in my area fuel is about the same (sometimes more) than gas and the costs to maintain it are a lot more. Oil and filter change for my T is about $15 (and I do it in my driveway). Oil and filter, and fuel filter changes for the 450 average between $80-150 (at a shop). The F-450 is an '05, 30K on it, my T which it's parked next to each night is a '93 with 125K and no oil leaks (touch wood) the F-450 has had a small leak from the rear main seal since a few months after I got it. Though my T could never do the work of the 450 I guess it's just a matter of choosing the right type of truck for what you need to do with it; I would never expect my T to be able to haul everything, as my hobbies have grown larger so have the trucks we use to haul stuff around with, for just hauling my quad or quick camping trip the T is hard to beat, for a longer multi-day road trip through three states with some light off-roading thrown-in than we take the 4Runner and when we want to haul our dune-buggy long distances with the quads than we take the full-sized truck and try to forget how many times we have to stop for gas.

BTW I've had a 2.25" Magnaflow muffler on my T for close to 80K miles now and it seems to work great! Gets a little deeper tone as it warms-up too which is an added bonus!

--Kevin