Break in oil change?

If Toyota isn't the exceptional brand, who is?

I'll let the resale value do the talking on Toyota's quality, or lack thereof. Last two for me returned 95% of the MSRP when sold (to dealers).

 

IMHO; Don't tell your dealership that your running 0W20 - Dealership can use that as a basis to VOID your warranty. You don't want that fight.
You've got at plug-in and running 80% in EV mode - so your only working the ICE 20% of the time. IMHO; I would do oil changes every 5K mile NOT every 6 months. That would be every-time the maintenance lamp turns on; that's assuming that the software is still on a 5K miles trigger base, like the gen4. As long as your using good quality, full synthetic oil, you should be good. If the oil turns really dark brown to black, then you need to increase the intervals, but I'm pretty sure your only going to be a light amber at 5K mile intervals. I do 10K changes on my gen4 and running the same EV-HV ratios as you are and my oil gets to be a dark amber or very light brown. I need to use a tissue paper to find the oil level on the dip stick for about a month, after my oil changes. I've calculated that I have around 7.5K max actual ICE miles on the clock. When I do run the ICE, I make sure it's running for at least 15 minutes solid - meaning engine gets up to temperature and then some to burn-out evaporate any moisture and fuel accumulated in the oil.

It's a different story for a non-plug-in.......

Hope this helps

PS: don't forget to change your ATF around 50K miles - that's turning all the time, no matter which mode your in...... I believe your transmission takes the newer specific ATF formulation as opposed to my generic ATF-WS.

Good Luck...

 

For 2023 model year at least, Toyota USA grudgingly "allowed" 0W-20, but advocated 0W-16 (see attached). They may have moved the goal posts since. Do you think a dealership would be able to discern oil weight, and they would be inclined to do that, and that a need to do that will arise?

And then, the Toyota Australia 5th Gen Prius Owner's Manual is likely still mentioning 5W-40.

 

My 2021 Prime calls for 0W16, don't know if the 2026 is down to 0W8 yet - but I know other Toyota engines started using that in 2024 or 2025.

 

Yep our 2017 Prius was 0W-20 but the 2021 Prius went down to 0W-16. I was half-expecting my wife's 2024 Corolla Hybrid to take 0W-08 but she, also, just takes 0W-16.....and I'm thankful....the 0W-08 is nearly impossible to find, still. (I buy oil all the time and only remember seeing it on the shelves once.)

 

I’d suspect this “downward motion” is in fact just decisions made ‘round a boardroom table, and nothing tangible has changed, with the engines.

 

Is it possible that, over time, manufacturing quality and tolerances have improved, and those improvements mean that engines built in later years don't need a thicker oil to compensate?

 

Funny, 0W20 used to be the bleeding-edge, thin oil. I doubt anything significant changes in engine design specs, for any year of a particular generation.

 

But I bet each engine is initially designed with the next oil in mind. For example, I bet the current M20A was designed with 0W-8 in mind. They introduced it with 0W-16 and then saw how it did. Once they got back enough engines with high miles to tear apart and examine(and once 0W-8 availability was high enough for the change to be feasible), they felt comfortable making the switch to 0W-8, model by model.

I was a little tempted to switch to it myself, but then Valvoline released Restore & Protect in 0W-16. Keeping my rings clean is my number one priority, so I'll go with VRP 0W-16 over TMGO 0W-8.



I personally find the whole "It'S ToO tHiN" argument rather irrational. Based more on "feelings" rather than hard data.