Just took my new 2005 E150 (155K miles) on a hard 2,500 mile run from LA to Portland and back. Much central valley to coast mountain miles covered and temperatures up to 110F at times and I'm very happy. Averaged 17 mph on whole trip and used almost no oil.
Transmission was still rough in and out of overdrive and at low speed in and out of first particularly when fluid very hot.
