This topic has been discussed extentively previously...
The 'HOLD' button is not 'O/D-off' button...
What Bro Pepsicola described is 'Over-drive-off' function... let me clarify...
Over-Drive (O/D)During normal driving, O/D is usually on (that's why u dont see any indication on your console)... in this O/D on mode, the car starts from gear 1 & it will change/ up its gear to 2, to 3, & finally to 4...
As we all know, at gear 4, the car is at its 'economic' cruising mode but lack the power to sudden overtake or speed up...
So, when u need to speedup, u will need to press the 'O/D' button to turn off the O/D... ie, O/D off mode.. (whoch the icon for O/D off is lighted on your console)... at this mode, your car will drop its gear to gear 3 & will not rise above gear 3 (ie. max gear is gear 3 only, will not move to 4). At this mode/ gear, your car will then regain its power to perform the climb, ie to speedup...
You will need to deactivate 'O/D-off' after your clim to resume to normal driving mode...
HOLDAt this mode (ie. when u press the HOLD button & the icon for 'HOLD' lights up on your console), your car will start from gear 2, & move up to gear 3, then to gear 4... it will not drop to gear 1 (even when u come to a complete stop & start moving again)...
This is a mode for moving off from a slippery road, ie wet or icy surface...
My Dumbo was equiped with 'HOLD' (& without the 'O/D off' function)... my observation is:
On a normal traffic condition & road surface... Car moves off more gently & comfortable with 'HOLD' on, as it starts with gear 2, will not experience the sudden jerk to 'push' forward when starting from a complete stop...
Plus when slowing down to a complete stop, with 'HOLD' on, my Dumbo will be able to cruise & roll forward further (ie without stepping on brake) without having to supply some acceleration (petrol) to make it move forward...
Thus, generally, I like to drive with HOLD on... have been doing that for atleast >2 years of the 3 years my Dumbo was with me... & I find that FC with HOLD on is better as compared to with HOLD off...
But there are bros here who find it the other way, ie FC is better with HOLD off then on...
So, I'm pretty sure about the mechanics & gear part of my explanation above... but as for FC, u will have to try it out yourselves...
the HOLD button is for overtaking and it delays changing gear while driving, hence normal drive not reconmended