I had a 2003 Tundra I think, mine had a camper shell and I got 15 mpg city/hwy and 11 mpg on tow. The truck was bulletproof and when I got it smogged they said that that particular model ran forever and was in demand. I can tell you that one of the common problems is that the solenoid goes out on the charcoal canister, it will cause a check engine light that will cause you to fail smog and a new canister is about 700. The solenoid cost me like 20 bucks on amazon and I was able to swap it in myself.
The tundra is a big truck, even bigger than my tacoma I had previously but it tows pretty much anything. It's a little hard to park in small lots for everyday driving but I was using it as my 3rd car and only towed my boat or hauled stuff in it. I liked it a lot and if I were looking for trucks I'd go toyota again. The only thing I did was change the oil and filter, everything else except that solenoid held up. I think I had about 200k miles on mine when I sold it and it sold pretty quick for 7500.
It really depends on what you plan on doing with it. I replaced it with a highlander hybrid. I get 28 mpg avg and 17 mpg towing my 4k lb boat/trailer. I cant haul full sheets of plywood in the hybrid or move couches or large items though, anytime that happens I'll just rent a truck because thats a rare occasion.