I usually change my oil at around 7 to 8K on my 06-V6 Toy 4Runner running a synthetic either Shell or PP. I now have 5K on the current oil and I am going to be towing my 5,000 LB camper aprox 2,000 miles in the next week and it will be hot. I will be working the truck hard so do you think I should let the oil run the full time of my usual 7 to 8K or do an early oil change? I guess I am a little worried from reading someplace that oil that has some miles and is heat cycled can leave lots of deposits or sludge in the areas of the engine?