[Polygon]

I think curtis said it best.

I would like to add that Mobil 1 is no longer a full synthetic. It is now a group III oil much like Castrol Syntec. If you want a fully synthetic then I'd suggest Royal Purple or Redline.

As for the conventional/synthetic myth. It is just that, a myth. You can switch over at any time. Some people swear is has caused their older cars to leak. I don't buy that crap and if that were true then the problem didn't lie with the oil, rather it lies with the seals. They would have to be bad regardless.

Also, the only time I would not run a synthetic oil is during engine break in. The synthetics don't allow the rings to seat properly during the initial break in. I would run it for about 20 miles to clean any excess crap out from machining, change the oil with conventional and run for 3,000 miles, and then I would change it again with synthetic.

Just an FYI.