According to the available data, the Toyota Highlander has a potential lifespan of up to 300,000 miles or around 20 years. This is a significant amount of time to maintain any automobile, but Highlander owners appear to be pleased with their investment. iSeeCars reports that 12.4 percent of Highlander owners keep their vehicles for more than 15 years, which is twice as long as the lifespan of the typical SUV.