I have passo 2008 and running as smooth as silk because of my perfect choice about the oils. Within city average is 14 and motorway its 17.5
Oil capacity is 3.5L You have to buy 4L and keep 0.5L save with you.
Kixx G1 10/40 is good. But DON’T USE IT because its semi synthetic.
To have ultimate performance, choose fully synthetic oil. And presently my recommendations for best available oils are
LM 5/40 grade oil name is "SYNTHOIL HI-TECH". PART NO. 2194. bottle is deep Purple color. Price 4800/4L. interval 8~10K
Kixx PAO (Group iv synthetic) 5/40. Green Color Tin. Prices ~3600/4L. interval 8K
PTT Performa Super Synthetic 0/40. Price ~ 3800/4l. interval 8~10K
PTT Performa fully Synthetic 5/40. Price ~ 3200/4l. interval 7~8K
Zic XQ 5/40. Price ~ 3600/4l. interval 8~10K
More than Engine oil, the transmission oil is important. It will take 4L transmission oil.
For better performance, buy LM's CVT oil which is THE BEST. Price 1800/L. Interval 80K
Or you can buy
TOYOTA CVT FLUID TC, 4L
Category: Transmission Fluid.
Product Name: TOYOTA CVT FLUID TC
Part No: 08886-02105
Type: fully-synthetic
Manufacturer: Exxon Mobil Japan
Volume: 4L
Interval: 40~50K
Price: 4800/4L
Tip: for better performance, change the both filters after every 4K.