Three years on two cars with no problems. The only time that you may have a problem is if using a crank trigger without a shielded and grounded crank trigger cable. If you are going to put the 8973 inside the car and use a crank trigger then make sure you get the shielded extension cable.
Also the start retard will not work because it puts the mag rotor too much out of phase for the low power spark to jump during start. Just zero the start retard and no problem.
If you are thinking about buying one then I would highly recommend doing it.
