Dealership used 0W16 instead of 0W20 for my 2017, is that fine?

That oil is wrong for the car. But I'm hoping the tech that serviced your car would know better and not put that in. I'm not even sure it can be corrected at that dealership. If you bring it back, you will not know if they actually drain the oil or put in the correct oil. They may just keep you car in the back for a couple hours and give it right back to you and say they fixed it.

 

There are several places on the internet (fwtw) where the two oils are compared via oil analysis, and each one I have seen shows they are nearly identical. If it makes you nervous, simply go back to the dealership and talk to the Service Manager (not the Service Advisor) and at least ask them to document it.

 

I've had a 2017 and now have a 2021 PP, both use 0w-16 as stated in the users manual here in CA. Look in your manual to make yourself at ease .

 

If that’s the case (not that I doubt it is), then you are much better off with that oil in there.

 

Here in Australia on a 2016 - they have a plethora of approved grades - and depends on the location (but no 0-16) - but then Michigan gets colder than most of Australia:

 

It seems like in 2019, when Toyota went to the spin-on canister oil filter for the Prius 2ZR-FXE engine, Toyota also changed the recommended oil spec from 0W-20 to 0W-16.


https://www.amsoil.com/lookup/auto-and-light-truck/2018/toyota/prius/1-8l-4-cyl-engine-code-2zr-fxe-j/?volume=us-volume
2018 Toyota PRIUS 1.8L 4 -cyl Engine 2ZR-FXE Variable Fuel
Capacity 4.4 quarts (with filter)
Viscosity 0W-20 (All TEMPS) - 0W-20 is the best choice for good fuel economy and starting in cold weather. If 0W-20 is not available 5W-20 may be used. However, it must be replaced with 0W-20 at the next oil change.
Torque 27 ft/lbs (Oil Drain Plug)

https://www.amsoil.com/lookup/auto-and-light-truck/2019/toyota/prius/1-8l-4-cyl-engine-code-2zr-fxe-j/?volume=us-volume
2019 Toyota PRIUS 1.8L 4 -cyl Engine 2ZR-FXE Variable Fuel
Viscosity 0W-16 (All TEMPS) - SAE 0W-16 is the best choice for good fuel economy and good starting in cold weather. If SAE 0W-16 is not available, 0W-20 oil may be used. However, it must be replaced with SAE 0W-16 at the next oil change.
Capacity: 4.4 quarts (with filter). After refill check oil level.
Torque: 27 ft/lbs (Oil Drain Plug) Install a new washer on the drain bolt.

 

As long as the engine oil looks and smells like engine oil, not ATF WS or brake fluid or oleomargarine or whatever, I’m sure it’ll be fine.

You’re correct that, for model year 2017 Prius cars built for sale in the U.S., the recommended engine oil viscosity is SAE 0W-20, per the Owner’s Manual (PDF), page 726. As previously discussed, however, I think that may have had more to do with the limited availability of 0W-16 oil in the U.S. at the time, than with any problem using it in the engine, for which 0W-16 has been the standard in Japan (Toyota Oil & Fluid Pocket Chart, in Japanese) since the introduction of the fourth-generation Prius model in 2015.