sejak menjak dah ada en.katak nie,kenala rajin amek tau apa function dia.klu tak sesia jek kegunaan en.katak.
O/D or overdrive nie mmg dh ada kt dalam keta auto.aku jek yg tak tau function dia apa. nie ada info sket.paham dah kot cmne nk pki dia :D

How to use overdrive Generally speaking, overdrive (O/D) is the highest gear in the transmission. On most cars the automatic transmission has 3 speeds and Overdrive (forth speed). Overdrive allows the engine to have less rpm with higher speed in order to have better fuel efficiency. When you switch it on, you allow the transmission to shift into overdrive mode after the certain speed is reached (usually 30 - 40 mph depending on the load). When it's off, you limit transmission shifting by third speed. In normal driving condition the overdrive should be always on. You may need to switch it off if you drive in mountains area. . You also may need to switch it off when you want to slowdown using the engine braking, for example, driving downhill.

dipetik dari : http://nismoclub.6.forumer.com/a/kegunaan-sistem-overdriveod-pada-gear-box-auto_post4620-15.html

ok en.katak? be more useful for me bebeh