[JimD]

When oil gets old it tends to get thin, lower viscosity, and may stick to surfaces less effectively. On a cold start you have no oil pressure for a brief period and you are depending on the oil film left from your last drive to lubricate the engine until the pressure comes up. If the oil film is minimal - because the oil has broken down - then you will do an abnormal amount of wear.

It's not clear to me that you can keep enough oil in the lifter to help much, however. It also is unclear to me that a little noise at idle is more than an annoyance. If the lifter "pumps up" with engine revolutions so that it results in the proper lift on the valves, then the noise at idle does not seem to be an issue with the engine doing basically what it is supposed to. I'd rather my car not sound like it has mechanical lifters with too much clearance but it seems most important that it function properly under load.

Annually or every 15,000 miles is not an oil change interval designed to maximize the lifespan of your engine. It will get it through the warranty period and will probably get you around 100,000 fairly trouble free miles but IMHO it is not going to make the 300,000 miles or so that a modern engine should be capable of. I change around 5,000 miles on a full synthetic. That may be wasting some money on oil and filters but I'd rather do that than be looking at a rebuild at 100,000 miles. I changed the oil on a Toyota pickup with nearly 200,000 miles on it Saturday. The owner changes oil and filter very frequently and it functions like a new engine. Experiences like this have convinced me to spend a little on frequent oil changes.

Jim