You have what sometimes seems like innumerable warning lights in your vehicle. Some of them alert you to very serious problems. Others, not so much. Some lights simply provide information, and your Gas Cap Light is one of those. When this light comes on, all you need to know that your gas cap is not present. Perhaps you have forgotten to screw it back on after fueling up, and you can consider this a helpful reminder that you should probably exit your vehicle and retrieve it off your trunk lid, or wherever else you might have left it.
So yes, you can drive safely with your Gas Cap Light on. Now, of course, you are wondering if you can drive safely without your gas cap. The short answer is yes. If you can drive with the Gas Cap Light on, you can drive without the gas cap. But what you need to know is:
Driving without your gas cap will not harm your engine.
Driving without your gas cap will not cause you to lose fuel. There is a flapper valve built into your car, and it will stop fuel from flowing out of your tank. The only danger here is if you were careless enough to lean over the fuel intake and provide an ignition source like a lit cigarette that could cause the escaping fumes to ignite.
Driving without your gas cap will not deliver harmful fumes into your passenger cabin.
The only real issue here is not safety-related – it is simply that until you replace your missing gas cap, you are going to have to live with a lit-up Gas Cap Light. Once you replace the gas cap, the light should go out. Sometimes, however, the system needs time to reset, so you may need to drive for a while before the light finally goes out. If it has not gone out within, say, a hundred miles, there could be other problems, and you should visit a mechanic to have your system scanned and the problem corrected. At YourMechanic, we can replace your gas cap for you, and also diagnose any problems that may be resulting in your Gas Cap Light remaining on even after the cap has been replaced.