[GTO JUDGE]

Weight on a key chain could in time cause problems with the key cylinder, or a wearing of the key itself. All those keys many have dangling on the hoop adds weight. When the key is in the cylinder the weight of all those other keys and or other items on the key chain is pulling down on the key fob and putting pressure on the key in the cylinder. All the added weight can cause a wearing problem inside the cylinder, and or cutting a grove or deep scratches in the key. To avoid this possible problem, only have the car's keys on that chain.

The best choice for lube in the cylinder is graphite. Graphite is a dry lube and bonds to metal surfaces causing a slick surface. Graphite is available in spray, and powder. I would use spray and not powder in a cylinder. The powder will cause a packing action if used too heavy. Any type of grease can be easily transfered to your pants pockets, and lint, and dirt will find its way into the cylinder sticking to grease. This in time will cause a gunky build up. WD-40 and a like will attract lint as well in time.