I once saw a friend, for no apparent reason, stick his key in another friend’s car door. To his surprise, it unlocked the door. I don’t recall the make or model of either vehicle.
More recently, my sister-in-law parked her '99 Mazda Protege diagonally across my driveway, then got in someone else’s car and drove away.
I had a key to a '95 Mazda Protege I’d previously owned. I stuck in the key, opened the door, and started the engine, only intending to move it out of the way. Then I figured, what the hell, she parked across my driveway, it’s my car now. So I ran all the day’s errands in the Mazda.
That’s the only time I have ever attempted to steal a car (or at least a tank of gas) using the wrong key. Sure, it’s only anecdotal evidence, but seems pretty coincidental if there are really thousands of unique combinations.
The key codes I deal with are a letter (which designates the key type) and a four digit number. I guess it’s not that many possibilities, but then again the tumblers in the cylinders are either brass or more commonly aluminum, so wear would certainly be a factor. Thus is the benefit of having a key with a chip in it that interfaces with the cars skim module. No chip, no deal. Even a screw driver or slide hammer won’t get the car to start. Hmmmm. Maybe that’s why they were invented. To keep some joker from stealing your car with a simple hand tool.
Your average automotive key has eight cuts on it. What are the odds another key would work? Seems improbable, but your experience suggests otherwise.
After a late night for my grandfather, my grandmother got up the next morning and went out to find their car had changed colour. It was even the same make, model, year! Later that morning she got a call from someone else who’s husband had been out late as well.
I think an easier explanation, may not be whether the keys are unique but that the lock barrels they fit are too similar or defective. I've had a couple cars where you don't really need a key anymore.
I suspect tumbler wear plays a big factor. If I stuck my Mazda key into a brand new car, probably nothing would happen. An older car may not be so picky.
If the key codes are unique, but the locks and starters are unable to distinguish between similar keys, then they’re close enough to say the keys are not unique.
That’s probably why different locksmiths gave different calculations for the number of combinations (1,400,000 vs 100,000 in the Jill’s column). Maybe some locksmiths recognize that a lock with key code A5555 will turn with key A4555, A6555, A5455, A5655, etc.
I agree that the chip (is it an RFID tag?) in newer keys is much more secure. It also means my '01 Corolla replacement key costs $2 while my '06 Ridgeline key costs $80.
A letter and a 4 digit number, where the letter pretty much designates vehicle make? Assuming the digits can be 0-9, that’s only 10,000 combinations for each of up to 26 key types.
I wonder how Locksmith Bob calculated 1,480,576 for GM and 65,000 for Chrysler.
Got me. I work for a Chrysler dealer. I suppose if you took all the models, some were manufactured by Mitsubishi and some by Mercedes, some models had year breaks using different types of keys, you might be able to come close. I would take Locksmith Bobs word on it.
In 1973, my mother bought a Plymouth Duster. One year later, my father purchased a Plymouth Satellite from a different auto dealer… The door/ignition keys to each car worked in the other. I’ve always wondered what the odds of this happening were.
This. My 80s-era Toyota Corolla was stolen in the mid 90s from a parking lot my office overlooks, in very busy downtown Seattle. It was recovered a few days later, with no damage at all, no forced lock, no broken window, just an empty tank. The cop who handled it told me that once the keys for some types of cars have the sharp angles worn off, they’re alike enough to be interchangeable. Enough assholes in Seattle knew this to exploit it regularly, and the cops were used to recovering undamaged vehicles of certain ages and makes.
In those days the keys only had 5 cuts. Still, they had they same kind of four digit code that modern ones do, just a diiferent letter in front of it. The main difference is that modern keys are double sided, allowing you to insert the key either way. Cutting keys fairly often there isn’t anything like inserting a fresh key into a fresh cylinder. You can feel the tumblers fall into place as each one hits its cut.
You know, come to think of it, I wonder why the keys with more cuts (8) don’t have a longer code. With eight cuts instead of four that should take it to the hundreds of thousands. Well, I’m not really smart so I’ll leave that to somebody with a brain to figure out.
Reminds me of a funny story that I would have trouble believing if it didn’t directly involve me.
My friends girlfriend, in a hungover haze, locked her keys in her Chevy Beretta one morning. We tried to jimmy the locks with no success. We tried the key to his grandma’s Chevy Tahoe becuase it was the same make of car, which didn’t work. After about thirty minutes and a hundred attempts at pulling the door handle, hoping it would magically open, she decided to call Pop-A-Lock. Before she called, I said jokingly, “Wait…we haven’t tried my car key yet”. I walked to the door, stuck the key in, turned it, and pulled the door open…with the key to my '99 Mercury Sable!
I tried for five minutes to repeat this astonishing feat with no luck. Lesson of the story - never give up before you’ve tried the absolutely absurd. Maybe you did put your keys in the refrigerator crisper or your wallet in the toilet tank :-).