I’ve had the Tundra for 3 years and have never measured the mpg. It’s my son’s truck and he’s out of the country. Is there a credible source for mpg? If not, I’ll probably filler up Saturday and take a 60 mile drive to find out. One source shows 17 mpg on the hwy. I happen to live in a mountainous area. V8, 4WD. Double cab.
60 mile drive is NOT going to give you an accurate measure of gas mileage…You need several gas tank fulls for “accurate” measurement.
Go to Edmunds.com and you can research the vehicle, get user reviews, and mpg as per EPA. Just over the rear view mirror on the headliner you might find a display that gives outside temp, mpg avg, mpg instant, and DTE distance to empty. Use the “mode” button to switch display options.
My '01 Sequoia is similar to your truck, same motor. I get just over 20 mpg driving at 60-65 mph on the expressway. Around town you can go as low as 14 mpg. I average about 15.5 to 16 mpg per tank.
Agreed that 60 miles is not going to tell you very much and a 4WD in the mountains could leave you slightly disappointed in the fuel mileage if you’re aspiring to 17.
Actually, I’ll be driving it downhill. 
Well, not quite, of course, I have to come back up it. The elevation difference is about 2000’. I have 5 gallons in the tank, so it’ll probably cost me about $75 to fill it up. However, when I make the trip down to Auburn, CA I usually do some shopping there, or another 10 miles to Roseville, 20 miles outside of Sacramento. I think I’ll probably just use Edmunds, as suggested above. Consumer Reports the mpg as 15. http://community.cartalk.com/posts/list/2274992.page#