I see the following points:Was the purpose to be "least as good" or to do preventative maintenance? If the capacity is 5.5 quarts, a complete change requires draining that amount and refilling that amount.
1. The poster drained 4 quarts of fluid from the OB at 50000 miles and added 4 quarts back. Should 5.5. quarts have come out?
2. The poster added 4 quarts of fluid back.
3. The initial response states that 5.5.quarts should have been filled according to the FSM procedure, and filling 4 quarts is a sure way to burn out the CVT. Should we assume that 1.5 quarts of CVT fluid leaked out at some time, and this leak was not noticed by someone who is not afraid to DIY a CVT drain/fill? I am sure the person would have noted a leak and potentially drivability concerns due to low fluid. I am also certain that overfilling a CVT is not desirable.
4. Where do you get your information that the capacity is 5.5 quarts. The capacity is close to 12.5 quarts.
In summary, if the car was run satisfactorily for 50K miles and 4 quarts were drained and added back, it will be fine. Unless the car had problems specifically linked to the quantity of CVT fluid prior to the change, there should be no consequences going forward that is linked with the exact same level of CVT fluid added, that was drained.
Counterpoint: If the car was filled low from the factory, then you are correct, a DIY person might not know this unless there were drivability concerns. The FSM procedure for proper fluid level has to be employed to be sure that the level is correct.
Separately, I just picked up 5 quarts of CVT fluid yesterday. My 17 OB is running exceptionally well. My initial thoughts are that I will drain and add the same amount back. I am aware of the drain and refill procedure. However, if only 4.5 quarts (as an example) drains out, I will at least add 4.5 quarts back. I understand that at first pass, I might only be able to add between 3 and 4 quarts and then would have to start the car, cycle it through transmission positions, warm up, letting it idle etc., and add the last bit of fluid until I have added up to 4.5 quarts (used in this example). If my car drains 5.5 quarts, then I will purchase another quart and add 5.5 quarts prior to calling the maintenance service satisfactorily completed. Per the FSM, the correct level is checked as follows:
1) Start the engine to raise CVTF temperature to 35 — 45°C (95 — 113°F).
2) Operate the select lever in P → R → N → D and D → N → R → P to circulate CVTF with the engine idling.
3) With the engine idling, lift up the vehicle and remove the filler plug.
4) CVTF is at the specified level when it is up to the filler plug hole lower section.