I have a 3.5 in my 15 Expedition XL. Combined city/hwy from purchase with 19k on it is 17.9 mpg. I've had trips with summer gas and long stretches on cruise that hit 24mpg, but am pretty much at 18 mpg city/hwy with little given up to any V8 I've ever owned in the power provided at the pedal. Haven't done any towing, but would suspect like others a precipitous loss of mpg. For the size and weight of the Expedition, the 3.5 is quite sporty without giving much up to any of the Tacomas or 4Runners I've owned in the past. In my opinion, it's much peppier that either of the Toyotas on thier best days.
