Most Smart car engines will last about 150,000 miles before they begin to require serious repairs. Some Smart car owners have reported their engines lasting as long as 200,000 miles with proper maintenance and care. For context, most modern car engines will last for about 200,000 miles or approximately 10 years.
However, the small size of a Smart car makes it slightly less safe than a larger vehicle would be. But even with its small stature, the vehicle still earns a 4-star safety rating from the National Highway Traffic Safety Administration.