Excessive oil consumption: Does using thicker oil help?

Sorry for the delay responding. So many things going on. It's more than a full time job keeping up with personal health and vehicle health!

We have not tried thicker oil yet, but are getting very close to trying it. Need to re-read this thread and find the other threads that talk about what the standard oil is for the Prius outside of the USA.

We've been told by several mechanics that they would never put anything thicker than 5W20 in a Prius. This, of course, gives us pause, as we aren't mechanics and rely heavily on our Prius for long-distance medical appointments.

Our Prius somehow passed Toyota's oil consumption test. It's very bizarre that the Prius passed, given the well-documented rate at which it consumes oil (we keep a detailed spreadsheet).

There are only a few possibilities:

1. Somehow, just during Toyota's oil consumption test, our Prius suddenly and spontaneously consumed less oil.
2. When Toyota began the test, they overfilled it with oil.
3. When Toyota began the test, they filled it with the wrong grade of oil.
   
4. When Toyota added 1qt of oil at the end of the test, they used an oil pump that wasn't properly calibrated, or accidentally filled it with more than 1 qt.

The only unique thing about the oil in the Prius during the test was that it was almost due for an oil and oil filter change at the beginning of the test. So the oil and oil filter were a little old. Not sure if that makes a big difference for oil consumption. (Please share your thoughts.)

Our choices are now to repeat Toyota's oil consumption test, or to give up and either switch to a thicker oil or try adding engine supplements.

The dealership stated that even with high rates of oil consumption, oxygen sensors and the catalytic converter should not be damaged. They said those were issues with oils many years ago, but is not an issue with modern oils. Hopefully, that is accurate.

 

How many miles you been using that? Change at 5K?

Thinking about trying Amazon's 5W30 before trying a 40.

 

Did you have oil consumption issues using 0W-20 or 5W-20? What about with 0W-30?

 

Thanks. Why did you switch to 0W-40 if no oil consumption?

 

That's what we've heard. Do you have reliable references for standard oils used by Toyota in other countries that use an identical engine and identical oil-related components (pumps/etc.)?