I own a 2008 DC Tundra, 5.7 and I was puliing an enclosed trailor filled with a friend of mine's stuff because he is moving. Now, I put the truck in tow-mode and the trailer probably weighed about 5000-6000 lbs loaded. I found that the truck was really working and when we arrived at our destination which was only 10 miles away, the smell that came from engine was as if it was overworked. Any suggestions??