now thats interesting.... much thanks for pointing this out. im attaching the snapshot below of the mentioned page.. 6.3 liters... i have changed it twice 4.0 liters each in the 5 years of my belta.. & no mechanic ever pointed this out before. still i think.. this needs to be discussed with seniors of this group as well as some senior Mechanics before meddling further with your Transmission. i would request the senior guys here to discuss & provide their input
i m also attaching a link with some info on the matter
Transmission Oil / 2007 Toyota VITZ Pakistan - Solving Car Problems
"infact the prime reason in most transmission failures is that the mechanics end up over filling the chamber, thus damaging the internal gearbox and pump seals. Here is what actually happened with my Belta 2 days ago: When you open up the drain plug for any of the K-series CVT transmissions which Toyota is putting in most of its newer models, only about 500ml or less of the transmission fluid drains out, leading one to believe that the transmission was running without oil, but that is absolutely not the case. The drain plug has an internal drain tube which extends about a little more than 2 inches inside the chamber, this causes the oil level to just drop till the mouth of this tube and hence the mystery disappearance behind the transmission oil. In order to fully drain the transmission oil, you will need to open up the oil chamber and drain out the fluid. This will also require you to replace the two gaskets which are firmly placed on top of the chamber. After completely draining the oil, about 3.8-4.0 liters of oil is taken up by the transmission.
Then to make matters worse, Toyota hasnâ?�??�?t really provided with a dipstick or a gauge to check the level of the transmission fluid. The mechanics even at Toyota Southern argued that the side housing nut is the correct place to feed oil from and that it should be filled unless it levels off around that point. The truth is that if you do end up filling to that level you would be over-filling the chamber with about 3.5 liters of transmission oil and that can cause some serious irreparable damage"
also check this DIY on pakwheels itself