Answer (1 of 11): At least one poster warned of engine damage… pretty sure that isn’t a real concern. That said, the gas cap is an integral part of the emissions equipment, absolutely on anything post-1996/OBD-II. How long/far you can go before the check engine light comes on depends on the make
How to know when your car has a quarter tank of gas - Quora
Does a car that sounds louder than usual when accelerating indicate engine problems? - Quora
What happens if a car is driven without a gas cap? - Quora
Is it true that it's better for your car to always keep the gas tank at least half full? - Quora
Why does the gas pump stop every 2 seconds when trying to fill a gas tank? - Quora
Is it a fire hazard that the US Army's M1 Abrams main battle tanks carry exposed barrels of fuel on top of the hull behind the turret? - Quora
Why is a car shaking while driving at slow speeds? - Quora
How long can I drive with the oil light on? - Quora
What happens if my car's gas tank cover is left open for a long time while on a trip? - Quora
What happens if a car is driven without a gas cap? - Quora