When racing and being a general hooligan in the streets you'll wanna be in pwr mode because the throttle and transmission will be more sensitive to abrupt changes in speed and throttle. Even at 1/2 throttle it'll know to downshift to the most appropriate gear where as with normal mode, say you suddenly lift off the gas while avoiding traffic or whatever it'll upshift to like 5 or 6th gear then take longer to hunt back down to a lower gear when you need to get right back on the gas to pass. In pwr mode it'll stay in the right gear longer and shift faster. Basically whenever you anticipate driving aggressively you'll want to switch over to pwr mode.

 

sorry... i was refering to WOT... but all the responses help. thanks guys! =)

 

I believe in full floored acceleration, the non ect pwr (regular) mode will yield faster times. It's the reason those who drag race their car tend to get better times in normal mode. I believe the normal mode actually holds the revs longer before upshifting.