If you live where it gets to over 100F in the summer and down to -25F (and colder) in the winter like I do the synthetic just gives me peace of mind. And then I just run it 6 or 7 thousand miles instead of 3 to 4 thousand and the cost is a wash.
This may well be true, although the owners manual suggests more conservative changes, and base their warranty on following maintenance guidelines. I feel short trips in extreme temps are "severe service".IMO, oil changes every 3-4k miles is wasteful. There was an article a while back (link no longer working), but this is what it concluded:
"Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources."
NOTE: this is for Mobil 1 Synthetic. My opinion is that if you're gonna change every 8k miles, then why use synthetic at all?