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was lightweight and affordable, with a 289 V8 - plenty of power for such a small car but not so much that it was costly to own. And it was absolutely beautiful, which counts.

In 1967 (and 1968), Ford made the Mustang a larger car and offered bigger engines, which increased the cost and lowered the fuel economy. The 289 was replaced in 1968 with a 302, a good engine but not as efficient as the 289. The car is still rightly considered a classic, but not like the original. Then in 1969, the car grew larger still. Ford progressively made the car more aggressive until the OPEC oil embargo of 1973 made customers reconsider the subject of economy versus performance, and then Ford almost ruined the brand with the Mustang II.

Ford continued to make the Mustang, but it didn't really recover its status until the 4th generation Mustang came out in 1994.