I owned a 2000 Tundra 4X4 and now own a 2002 Ford Diesel F350 4X4. As far as mileage, my Tundra got no where near the 23mpg someone mentioned. I got 13 in town and 10 towing a 4500 lb fifth wheel, that's at 5000+ elevation. I got up to 19 unloaded highway in Texas once. My diesel gets 14-16 empty and 12-14 towing around 10,000 lb. Also right now diesel is more expensive than gas.
If it's your daily driver, seriously consider the Tundra. Mine had the best ride and nicest interior of any truck I ever drove - nice and soft, but firm enough with the Bilstein shocks (TRD package) and super quiet in the cab, no wind noise, etc. I'm compaing the Limited package to my Ford's Lariat package.
Beware of brakes before mid 2001. I had mine fixed 4 times within the warranty period and finally they upgraded them. Mid 2001 on had upgraded brakes. Maintenance is also much cheaper on gas trucks. Oil changes are cheaper, filters are cheaper, brakes are cheaper, etc.
If you ever think you will want a bigger enclosed trailer or camper, consider the Ford. The power of the turbo over a mountain pass is worth the cost for me.
I just wish Toyota would come out with a one-ton diesel. That would certainly drive them to the number 1 position over GM.
