The manual says 10k miles. That is written by engineers and developers at Toyota and you should be fine going by that schedule. There is nothing that says to change the oil for the first time before that 10k mark.
Now, I only drive about 10k miles a year in my truck and I choose to change it every 5k miles, which is about every 6 months. I realize it contradicts what the manual and Toyota say, but that is what I am comfortable with. Sometimes the Toyota service guys look at me strange for requesting 5k oil changes, but what do they care? They are making extra money. Obviously, if you choose to change it before the 10k, its not going to negatively impact your vehicle at all. Just your pocket book a little bit.
This is the most realistic advice regarding this subject. It's the culmination of 6,549 threads.
On a side note! Why did the Toyota engineers say oil intervals should be at 5k for the 2010 models and change it to 10k for the following years? Did they realize the exact same engine could go longer after a year of service? Or does it just so happen to be at the same time they provided the '2 year maintenance plan' for free?
I have a 5th Gen also and it came standard with synthetic oil, that could be the reason for the change; perhaps 2010 and older did not use synthetic oil?
Anyway I just hit 10k this week and had it changed. If it were a Jeep i'd say change it every 3,000 miles ;-) but a Toyota running synthetic? I'm good with a 10k interval.

All I'm saying is, change your oil when YOU want to. It's your truck.
I agree completely. But, if you stay with the 10k interval, as specified by the owner's manual, and drive under normal conditions, you should certainly be covered if something went seriously wrong with your engine (as long as you have documentation that you performed regular maintenance). All I am saying is that Toyota's engineers and developers must be awfully certain of this, otherwise engines in their millions of cars would be failing early and they would have a HUGE headache. That being said, I guess I am still a little old school and cannot completely wrap my mind around a 10k oil change. But, that is just me and my anal retentiveness.
Sure, for a whopping 3yr/36k miles. The engines would probably last that long without ONE oil service.
Let's see, Toyota pays for your oil service for the first two years of ownership. We'll say the average driver does 15k a year. So that's 30k or 3 oil services. Let's just assume it costs Toyota $50 for every oil service (cost of oil, filter, labor, overhead, etc). Toyota ONLY sells 100k units this particular year. You guys should know Toyota sells over 9 million units per year.
1 vehicle costs them $150 in the first two years of service.
$150x100,000=$15,000,000
Here's the easy part. Now let's go back to 5k oil service intervals. 6 oil services in 3yrs.
$300x100,000=$30,000,000!!!
Imagine the savings at 9 million units!
As I stated before and most of you agree. Change it when you want to. I, personally, don't care if I invest an extra $150 per year in excessive oil services. It's my money and my truck. I'll do 10k oil services when Toyota warranties my engine for 150k miles. Not 36k.