Locked gas cap


i have a 97 merc tracer, do i need a locked gas cap to prevent pilfering? was told that cars can’t be siphoned anymore. is that true??


Why make it easier for potential fuel thieves? Buy a locking gas cap. Remember that a lock on anything is really just to keep honest people honest. There are many other methods being used these days to steal your fuel. Nothing is crook-proof. It’s just another obstacle to be overcome through creative reasoning. But you just might have a lot of lazy dummies in your area who won’t/can’t be bothered with anything that isn’t easy. Think locking your doors, removing the ignition keys, etc. All good deterrents, but if a thief wants it, they’ll figure out a way to steal it. Now consider the cost of a locking gas cap as opposed to the cost of, say, 5 gallons of fuel. I think that locking gas caps go for around $20. At today’s prices per gallon, that’s also about $20+, most likely +. Think of it as an investment, not a purchase. And who’s to say that they won’t take more than 5 gallons? As for pilfering, think about this. For under $20, anybody can purchase a flexible bulb-type siphoning pump, hand operated. “Bye, bye, fuel!”


If it’s a remote release gas door, as most modern cars are, you do not also need a locking cap. And an aftermarket locking cap may create problems for the Evaporative Emissions System, which requires a good and proper seal.


Because of the Evaporative Emissions System, I would suggest buying a genuine Ford locking gas cap from the parts department of the Mercury or Ford dealer. Aftermarket models may not be as compatible with your evaporative emissions system as they claim to be.


Alas, it is quite easy to siphon gas, even from a modern car. And for those who want to learn, there are many, many videos posted all over YouTube in which sleazy characters show us how to do it. I even learned that a locking gas cap is not much of a deterrent. There are only about a dozen different keys a thief needs to unlock any aftermarket cap. And a locking gas door is even less of a deterrent; the lock is so flimsy the door can be pried open on two seconds.

So my conclusion is that all precautions will be in vain. If a thief selects your car from all the others in the parking lot, he is going to win.


OK so you a locking cap so they punch a hole in the tank to get the gas, and they are. You buy a new tank, installation and fuel. Don’t bother with the locking cap. Best bet is finding a safe spot to park.