[Mr V]

Originally Posted by JohnFogarty

I'll say this since I was the victim of a rarer mechanical failure in the ignition of my Avalon. I would bet that it would have been cheaper to fix if it was only an electrical problem.

(By mechanical failure I mean that the key got stuck in the ignition and no one could get it out.)

Pro tip, your key chain that has your ignition key really shouldn't have anything other than the car key, the remote fob and maybe one house key. That extra weight increases the wear on the tumblers and can lead to the failure you describe though the more common failure is that the key won't turn the ignition lock cylinder. Note many will tell you that you shouldn't have your house key on there in case someone car jacks you since you likely have the registration in the glove box and that registration likely has your address on it.

Originally Posted by FrankJ

Of course your old fashion mechanical key can be copied for a figurative dollar anywhere keys are made. Your key fob can cost upwards of a couple hundred dollars to have a copy.

Another example of mechanical verses electrical is carburetors verses fuel electronic fuel injection. A simple carburetor is cheaper & more reliable than fuel injection. As you add demands to the control scheme eventually electronic fuel injection becomes a better choice.

Ultimately this is a chicken or the egg question.

Well the majority of cars nowadays have transponders in them and they can get expensive to replace depending on the brand of the car. Not only the key itself but many need a scan tool to program the car to accept then new transponder's code. A friend bought a used Honda that came with a single key, he spent $120 to get a second key and have it programed. On the other hand if you have a Ford or Chrysler product and you've got two keys you can program more keys yourself in about 30 seconds. Purchase one online and get the key person and your local hardware store to cut it for $1 and you've got a new programed key for under $20. Many locksmiths and hardware stores will also clone an existing key for $50-$60.

Originally Posted by magnets

The push-button start and key start of modern cars both involve the same amount of electronics. If you turn a key on a new car for more than 20 seconds, the starter automatically stops. The same thing happens if you try to start a car that is already running.

The key on my car lets me turn on the radio, start my car, stop my car, and remove the steering wheel lock. On the steering column, there is a device that allows me to lock my steering wheel when I have the key out, unlock my steering wheel when the key is in, and shift out of park when the brake pedal is pushed and the key is turned. Just like the doors and locks in my car, the system has never failed. The system is simple, and works every time, even after 230,000+ miles of driving. Why fix what isn't broken?

Not all newer cars work that way. Yes some are set up so that turning the key to the crank/start position sends a signal to the power train control module. The PCM will usually then ping the transponder to see if it is a key that is registered in its memory and then check if the engine is running. If it determines the key is valid and the engine is not turning it will then operate the starter until it senses that the engine has started or for a predetermined amount of time. However there are still newer cars out there where turning the key to the crank/start position just sends a signal to the starter relay and the starter will run as long as the key is in that position, even if the engine is running.

Many modern cars don't have steering wheel locks anymore, the thought being that since you can't hot wire it due to the transponder in the key the lock is not needed. On the other hand some cars have transponder bypass modes so you can start a car in instances where the transponder system has failed. They commonly require you to enter a code via actuating switches that don't seem related to starting the car. Here is the process for Honda built vehicles, I'm only posting this because the "code" is unique to the vehicle and normally only available to someone at an authorized dealer to look up. http://automotiveandcommerciallocksm...edure-for.html

Then there is the case of snooping and capturing the transponder code, cars with push button start where you can leave your key in your pocket are most susceptible to this. Their transmitters are often motion activated so while you are walking along with the fob in your pocket you are sending out the code. The older transponder in the physical key is less likely to be able to have it's code snooped since it requires a very near magnetic pulse to cause it to transmit.