oil change?

Most current engines running full-synthetic oil don't need oil changes sooner than 10K miles. A lot of that is the quality of the oil.

 

If you read the Toyota Warranty & Service guide (a separate booklet) carefully, you'll notice that Toyota makes no mention of synthetic motor oil. What they do say is the you can go 10,000 miles on 0W-20 oil. If you don't use 0W-20, then they want you to change oil at 5,000 miles.

 

First, a clarification: the official 3rd gen US oil change interval is 10,000 miles or 12 months, whichever comes first.

Some thoughts:

1. I agree, Toyota makes no mention of synthetic. All they spec is an oil grade to use. Around the world they spec more grades than just 0W20, still I think the recommended grade is 0W20. There's a few owners here that are regularly putting in 5W30, no problems.

2. If you're concerned about the long US oil change interval, keep in mind: it's your car, not the service writer's. To put his mind at rest (chuckle), you could mention "severe service". This doubles up the miles and time interval, to 5,000 miles or 6 months, per your 2nd gen.

FWIW, Toyota Canada specs 8,000 km (~5,000 miles) or 6 months for 3rd gen. I'm similar mileage as you, actually more like 500 kilometers monthly, and every 6 months, it's (DIY) oil change time. For me it's a couple of hours chore, and about $30 in supplies. Keeps me occupied.

FYI, Toyota Canada has gone to the US oil change interval (16,000 km or 12 mo) for 4th gen Prius.

 

0W-20 is only available as a synthetic or synthetic blend oil; by specifying the weight, Toyota has already specified a synthetic oil.