After three years, cars such as the Cadillac DeVille, Mercury Grand Marquis, Ford Taurus, and Chevy Cavalier is worth about half of their value, according to Runzheirmer International. But some cars maintain their value better, such as the Saturn sedan, whose value slipped by about 35 percent after three years. According to a spot analysis of six vehicles conducted by Runzheimer, vehicles depreciate as much as 32.5 percent for the Cavalier to as little as 17 percent for the Saturn after the first year. After the second year, depreciation figures range from a high of 43.4 percent to a low of 26.6 percent. Third-year depreciation ranges from 51.8 percent to 35.5 percent. After four years, a vehicle could be worth only 59.5 percent of its original value or as much as 44.8 percent.