IMNSHO
Take everything DEpointfive0 said and dial it back a notch for the average daily driver. Everything he said is spot-on if you want to squeeze every last bit of longevity out of your engine (or you are an obsessive Chemist heehee), but how many are going to keep their Z for 10-12 years?
I put it in the same category as the does-downshifting-wear-out-the-drivetrain-faster question - running less than perfect lubrication/driving habits decreases the life of the engine/drivetrain
slightly, but it doesn't do enough damage to really matter (as long as you are reasonable about it).
Once the warranty runs out, I plan on using a full-synthetic and a high-quality filter with changes at 6000-7500 mile intervals. Just about any modern, name-brand oil will do a great job, but I think synthetic is cool. I wouldn't be afraid to run a top-quality petro-based oil, but would shorten the change interval to 4000-5000.
Probably overkill, but I can be a bit obsessive, too.
PS: I change the oil/filter in my pickup truck, but not the Z. The car is too close to the ground and I don't want to mess with that shield. Well worth the $20-30 just to avoid the aggravation and I don't have to buy ramps.