Changing every 20K is overkill.

CVT is not running as same as ATF.
In fact the functionality mechanism of CVT is not as same as ordinary auto gear box with ATF.

Even with ATF, the recommended change interval mostly around 40K, (depended on the oil situation as well, sometimes after 20k, if the ATF oil show "blackish" then it is time to change disregard it is only 20k or less, but in normal condition with good quality oil, ATF should still look reddish after 20~30k, from my experience)

So far what I gather from the CVT oil changing need from the service personnel, it should able to last more than 60~80K.
Oil is changed when needed aka inspect the CVT oil quality to determine the need of change.

I cannot confirm the statement by service personnel is correct or not, just it is the answer given by both service personnel I had met.

If CVT oil really need to be changed every 20k, surely service centre would want every driver to change it in the service manual.
As by not mentioning in the service manual and not insist customer to change it, if CVT part does wear out due to it,
it could jeopardise their warranty liabilities as most car is having 3 years warranty, which could means around 80~100k mileage.

Just like they insist engine oil being changed every 5k or 10k, if not 3 warranty may be voided.

Actually, becareful about changing CVT fluid outside, make sure those workshop mechanic is well verse with CVT oil, as there was story mechanic pour ATF oil instead of CVT. (auto-gear so pour auto oil lor, and ATF is auto oil...)

This post has been edited by cherroy: Jan 15 2014, 04:37 PM

I find this youtube can be useful and understanding about CVT oil.

In the short clip, it has mentioned CVT oil is expected to last until the life of the vehicle (5 years?, we need to find out the life of vehicle definition), while some manufacturers recommend to change every 60K miles, or change every 60K miles (equivalent to about 100K KM) if drive at extreme condition.

http://www.youtube.com/watch?v=AbkdY-Ty_4o

This post has been edited by cherroy: Jan 18 2014, 03:31 PM

You want to "test out" the CVT gear box that easily can cost 5 digit to see ATF can be used or replace CVT oil?

CVT oil properties is different with ATF, because the functionality and mechanism is different with conventional 4 gear auto-transmission.

You change a fluid when its properties degraded that could harm the functionality of parts, this is basic engineering knowledge instead put a statement please don't ask why must it be changed so fast.

If CVT oil is really need to change every 20k if not the gear box would spoil, then the manufacturer will be the one first to tell customer or insist the customer to change, as they are more afraid the warranty claim, if the gear box can spoil if not changing the CVT oil at 20k interval.

Just like the engine oil, manufacturer insist customer to change at first 1K, 5k, 10k interval on engine oil, if not manufacturer may not oblige for the warranty on the engine.