This UOA represents oil that was in use from 5K - 10K miles. I believe the higher-than-normal silicon is from gasket sealants - This has been my experience with Toyota V8s. Although I agree I could probably extend the oil change interval to 6K, I won't because the truck is under warranty - and Toyota has gone to a 5K limit regardless of whether it is in normal or severe service - So I don't want to void the warranty by exceeding 5K.
Also - This engine is equipped with an engine oil cooler - as part of the optional trailer towing package. It's immediately above the oil filter. Are these made of copper internally? Perhaps that accounts for the slightly elevated (in my opinion) copper level.
Filter used was a Mobil 1 M1-209. Oil was Mobil 1 Extended Performance 5W-30. I plan to try the new Amsoil filter soon - Do you think this will make a difference on the particle count? Any other comments?