If it drives well and you enjoy it, just keep driving it. I had never had a vehicle past 100k until my 07Exp, and began worrying that I should upgrade, but kept driving with very few problems. Had a minor leak in transmission cooler at 150k, changed all the hoses at 200k and at 220k replaced the fuel pump...the truck never spent a single night at a repair shop, but got regular maintenance. As my work and travel truck it got heavy use, towing boat and equipment trailers...and continued to drive just like it did when I purchased it. At 233k I upgraded to 13Exp...hoping to get a repeat performance with very similar truck.