Interesting thread, but I think it's a bit out dated now. Doesn't look like Castrol 'Edge Extended Performance', Castrol 'GTX Magnatec' or Pennzoil 'Ultra Platinum' were tested. Would be interesting to see this updated. My Dad has used Mobil 1 in all of his car which he drives to 100k+ and has never had any problems. I've got 4 free oil changes at the dealer through the Wave program, so will use those first, and will ask for full synthetic, even if I have to pay the difference from conventional. I read a lot about oil before choosing one for my out of warranty Porsche. Funny thing is after all the reading, I chose an oil not approved by Porsche, and w/o API certification. Many people who know Porsche m96 & m97 engines (essentially water cooled flat sixes from 1999-2008) will suggest using Joe Gibbs Driven DT40. I see Driven makes both a 5W-20 and a 5W-30.
http://www.drivenracingoil.com/dro/products/street-performance-engine-oilshtml I may try them after I'm out of warranty. Some people who know m96 & m97 engines very well say Mobil 1 is very good at keeping the engine clean, but not so great at preventing wear. Only downside I can see with the Driven oils is the added ZDDP may wear out the cats quicker. To me, however, cats are cheaper than major engine work.
