Most dealers give you an oil change every 10,000 miles, up to 25,000 (which means 2, really).
Toyota calls for that engine to have 0-20 weight oil. That is only available as synthetic.

 

At one time, the 2GR-FE engine had a 5k oil change interval. The maintenance minder was set up to begin flashing at 4500 miles, and go solid-on at 5k miles. A few years back they extended the oil change interval on this engine to 10k miles under normal conditions, 5k miles under harsh service or extreme environmental conditions. However, they neglected to update the dash software!

As a result, on our 2015 Limited the nice pretty center display locks into Maintenance Required!!!! at 5k, and you have to push buttons to get it to shut up each time you start the engine. Now you could cancel it out yourself and reset it for another 5k miles. Instructions to do so are in the owners manual. Or, what I do is return to the dealer every 6-7k miles and tell them that your usage and weather conditions justify changing it early (a compromise between harsh and ideal). In my case they've gone along and changed it for free.

 

This isn't entirely true. Yes, the interval is 10k miles for an oil change, but they did not neglect to change the dash. Its just the 'maintenance required' light that shows up every 5k. The dash is alerting you to your 5k maintenance cycle which is tire rotation and check fluids, and other crap as stated in the owners manual. Not saying you really need to do this at 5k, thats a different topic in itself.

http://www.actontoyota.com/toyota-scheduled-maintenance-intervals-sienna.htm

 

^^
Yes, all true.
Owner can set the interval to a different number.
5K is a good interval to AT LEAST give everything a good once over.
Oil change intervals is a topic that requires a lot of popcorn.

 

Doesn't toyota care cover oil changes? Last year my battery died, bad cell.
Our 2015 XLE had under 5000 miles and they did an oil change and service.

 

My dealer covers oil changes every 10k miles, even on my used 2013 Sienna. They use full synthetic 0W20 oil, as the manual recommends.