How much time between oil changes?

that's what makes it such a great car, lifetime fluids

 

Wonder what Toyota's def. of "lifetime" is.

 

Heck I remember my POS American made cars in the late 70's and 80's that could barely make it to 100,000 miles before throwing a rod or burning a LOT of oil. I remember checking the oil that only had 2,000 miles on it and it being as black as night! Yet the Honda's and Toyota's (rice burners) I saw seemed to last forever!!

 

For my 2022 Prius Nightshade the only fluid that comes close to "Lifetime" is the transmission fluid, PROVIDED you don't drive while towing (which it is not approved for anyway) OR drive using a car top carrier OR (AND THIS ONE IS A GOTCHA!!) driving with heavy vehicle loading.
Ignoring the first two, the third one is where any hope of calling it "lifetime" will pretty much go out the window for the "average family" in the United States. Using CDC, Census, and airline figures, here are some calculations.
Average family size 3
Average adult male weight 199.80 pounds;
Average adult female weight 170.80 pounds
Average weight of child (11-16 years old) 155.80
22 pounds for carryon luggage (lowest limit I was able to find); 22 X 3 = 66 pounds (think of brief cases, purses, book bags).
From the label inside the drivers door of my Prius: "Combined weight of passengers and cargo should never exceed 825 pounds".
So a family of 3 could very easily weigh 592.4 pounds for even short trips. That comes to 71.80% of the vehicles cargo capacity.
Based on rule of thumb for RV use, that would be considered at least approaching "heavy vehicle loading".

Add in a couple of bottles of water, the family dog, etc. etc. etc..... much less any camping gear or luggage for that weekend trip, or any groceries (a gallon of water weighs 8.3 pounds and milk is heavier), and we can pretty much throw out the "at least approaching" idea.

All of this boils down to the average family should be changing the transmission fluid every 60,000 miles or 6 years. AND BTW, also should be changing the oil and filter EVERY 5000 mile or 6 months (based the same requirement of "heavy loading"). At least that's what the maintenance schedule calls for.

FWIW, a stroll through any Walmart will convince you those "average weights" are EXTREMELY optimistic,