Brian:
As you're beginning to see from these posts, the real answer is "It depends":
If you're expecting cooler weather in San Diego this Winter, like never getting over 75 degrees F, then 10W-30 might be OK. Personally, I am running 10W-40 Kendall right now in my 2110 (still breaking it in at about 3000 miles), since I expected it to see warmish temps during the winter here in South Carolina. I also have a fan-powered oil cooler, which makes a BIG difference in what oil I choose. Full-flow oil coolers typically run full oil pressure through the cooler and filter, which can be WAY over 150 lbs pressure on start-up. If it's cold out AND you're running really heavy oil, like 20W-50 wt. or something, your engine/cooler/filter could possibly see over 250 lbs pressure on start-up (the reason some folks have seen exploded oil filters on this forum when they start their car on a really cold day).
I don't change as much per mileage as per the seasons. I've been busy changing things on my engine and never got more than 1500 miles on it before an oil change, but that may begin to stretch out from now on. Typically, I change every season, since it's easier for me to remember that than fiddle around with mileage, but that's beginning to look like about 3000 miles between changes.
I've also tried synthetics on several engines (including the 5.4 liter on my current F150 pickup) and while I find that they work pretty well and as advertised, the engine (every one of them) tended to weep oil past the seals SOMEWHERE. Once I went back to "regular" oil the weeping stopped. I also tend to run synthetic FAR longer between changes (again, only in water cooled engines); typically, I change only filters at 3000 miles, adding enough oil to bring it back up to "full", and will change BOTH oil and filter at 6000 or 9000, depending on whether I've been pulling a trailer or not. If I were using Synthetics on a non-filtered VW engine, I would still change every 2K - 3K miles, which gets expensive. On a filtered VW engine, I would probably go 5K - 6K miles, but that's just me - not everyone would do that, I know.
If you've got about 400 miles on your car and going to change the engine oil, don't forget to change the transmission oil, too. You could opt for synthetic 90 wt. Hypoid oil for the tranny at this time and probably see easier shifts, too. After changing tranny oil at 400 miles or so, it should be good for 25K - 30K miles, at least, as long as it doesn't leak.
Gordon
One of the "Speedstah Guys" from Port Royal, SC