I've always been told that as long as you use a half decent quality oil (with the right viscosity) and do your regular oil changes, an engine should leap into 200,000 territory

I use Mobil 1 5w30

 

The only thing I would like to add to this "discussion" on oil is that, I use Mobil1 15W50 in my turbo engines and in my race car exclusively. Primarily due to the fact that by using the thicker oil, it maintains a thicker film strength at high rpms. Understand that my race engine spins at 8500rpm and my turbo's center section spins at over 100,000!!!

My 2 P.S.I

 

And that same oil would lead to start up starvation in the Maxima (especially in the colder climates).

If you're using a very good full synthetic in your race engine, then using 15w50 won't make much of a difference over 10w30 (we're talking same brand here) for your engine life expectency. If you're using a cheaper synthetic that will break down while you're running hard, then yeah, starting off with a 15w50 oil will help you out some...but you're still using a crappy oil at that point. It'll still break down (although the time it'll take to get to the point of a major mechanical failure will be longer than the 10w30)...

Those are my pennies worth