Since most cars have enough fuel for just about 500 kms or 7-8 hours. So in a way that places a limit on how long an engine can be ON continuously. An engine can run for as long as the fuel in the tank lasts.
The Mahindra XUV300 is the safest subcompact SUV with a complete 5-star rating. Its range-topping variants feature up to six airbags, front and rear parking sensors, and ESP.