what weight do you use on your 2007 V8?
I haven't changed it myself yet, so whatever the dealer put in there. 5W20 is likely if they are trying to only stock one kind of bulk oil, but maybe they still have 5w30, too? The service advisors are not exactly knowledgable, so there's no point in asking. Probably whatever is cheapest because they only charge $25, even though this engine takes 6.5 quarts.
I'm planning on trying 0w20 because it should decrease wear when then engine is cold, and maybe improve fuel economy slightly (the biggest gain would be in cold weather and short trips. At operating temperature it's in the same range as 5W20).
I could do a used oil analysis to get an idea of what's in there now, but for $25 I don't think it's worth it. I do plan to save a sample in case I decide down the road that I want a baseline UOA, since I plan to do a UOA on the 0w20 around 5,000 miles to make sure everything is OK.
I plan to add a block heater when I change the timing belt, maybe this fall. I don't usually have a place to plug it in, but if I move somewhere with more convenient parking I plan to plug it in for a few hours before every time I drive, at least in cold weather, so that might somewhat negate the need for 0w20.
I looked into filters a bit, and it looks like the Toyota filter 90915-YZZD3 is good quality and easy to obtain. A lot of people like the Japanese 90915-20004 filter, but they are hard to obtain, expensive, and I saw no evidence that they are any better than a regular filter.
This thread shows that Amsoil's filter is more efficient than Toyota's, but it's a test by Amsoil so it would be good to find an independent test. Also, I don't know how they define efficiency. It might not be a useful measure of performance.
SHO Denso OEM Oil Filter vs Toyota Denso OEM Oil Filter
This thread shows that the Toyota filter is larger and has more surface area than the competition.
Toyota Oil Filter (Made in Thailand) vs. the competition........ - Tacoma World Forums
Here's a good report on the Amsoil filter.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Main=66157&Number=846034#Post846034
And a discussion of what the Amsoil test results mean.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1379904
I can't find a place to buy the Amsoil filter except from them directly for $15, so I think I'll get the YZZD3 from the dealer when I get the crush washers I need for the gear oil and engine oil. It should be about $5, but if not Amazon has them for around $7.