The only mechanical problem I have had with this truck was the odemeter quit working at 300 miles. The Toyota warranty covered this repair and I haven't had any other problems with the truck in 61/2 years. I towed a 17' boat for the first 3 years, and never had any problem pulling the 2000 pound boat and trailer through the Black Hills. Normally while towing I could do 62 miles per hour at 3000 RPMs. The toyota Tundra's offroad capabilities depend on the tires you choose to put on the truck. I do a lot of off-road driving for work in the Black Hills through a lot of mud and snow. I changed out the factory tires for a set of BF Goodrich All-terrains and have never been stuck.
The V-8 engine, Smooth ride with excellent acceleration. I have had no mechanical problems with this motor. With the right tires, this 245 horsepower truck will take you through snow and mud with no problem.
My only complaint is the gas mileage. I get 13 MPG with my heavy foot. The 2007 V-6 engine has 236 horsepower (which is enough for my needs) and gets 20 miles per gallon. However, you cannot purchase this model truck in 4WD which is crucial for traveling in snow country.