I was actually thinking about this yesterday,normally closed would be better,no draw on the battery while the truck is sitting and the solenoid wouldn't have as hard of life,so less chance of failure. Normally closed its engaged 30 minutes a day while your driving. Normally closed its engaged 23.5 hour while you are not driving. As for failure if it fails you have to bypass it on the road,a piece of tubing that's it. Your ignition coil,ignition module,fuel pump,ignition switch etc.etc if they fail your stuck we don't worry about failure,we use good parts,and fix things as needed.