maximaman69

Ok, someone explain Overdrive to me. I thought I knew but maybe I don't after the last few days. I was climbing a hill and the car kicked from 5th gear to 4th gear. I then turned off OD (thinking it wouldn't have an effect) but it kicked my car into 3rd. I thought OD only kicked your car into 4th gear and wouldn't have an effect if you were already in 4th. I've played with it several times and it always happens like that.

Does our OD kick into the next lower gear regardless? If I am in 3rd, will it take me to 2nd?

UMD_MaxSE

iTrader: (1)

OD is basically 4th gear on your auto tranny (there is no 5th). Your car will shift into OD around 45-50 mph under light throttle and later depending on how much throttle you are applying. Turning off OD will lock out 4th gear. So, if you are in OD, it will drop you into 3rd.

punkdork

DAMN!! You beat me!

theMax

Overdrive is a weaker gear and has no (less) power. It is used to cruise at high speeds and not accelerate. Other gears make the tranny spin faster than the engine (according to the gear ratio), the overdrive gear makes the engine spin faster.
When you are in a hilly area take the OD off.
Some cars actually change the RPM's where the car shifts when the OD is on/off. I'm not sure about the MAX.
Bottom line OD is good for your engine but bad for power (accelerating).

UMD_MaxSE

iTrader: (1)

hehehe...sorry man..... next time

jeffil

OD will actually kick in under very light acceleration at
about 37 or 38 MPH. Even slight pedal push will take it
back out. That's much too early in my opinion but Nissan
tells me that's what engineered into it. It keeps their
gas mileage figures up.

SteVTEC

In a manual transmission you have one gear solidly locked and there is no "play". In an automatic transmission you have a torque converter, and there's always a little bit of slippage, so it's sorta like a manual only you'er always slipping the clutch a little bit. But once an automatic transmission is in its top gear it'll lock the torque converter so that there's no more slippage anymore. This makes the tranny much more efficient. But it can't lock in every gear because then it'd wear itself out much quicker because it can't shift gears if the converter is locked, so it only locks in the top gear.

But as far as the whole shifting thing goes, you could sorta say this:

1st Gear => 1
2nd Gear => 2
3rd Gear => D (O/D OFF)
4th Gear => D (O/D ON)
Quasi 5th Gear => D (O/D ON) (Torque Converter Locked)

So if you're cruising on the highway and you get on it a bit and the revs jump up suddenly, it's not actually a downshift (although it feels like one), it's just the torque converter unlocking so that it has the "play" back and can build up the revs a little more to give you some more torque multiplication.

maximaman69

Thanks, that makes sense. I kept thinking it was downshifting but you have corrected me. I appreciate it!

Dario

iTrader: (1)

Man i could feel the difference today as i was trying out the OD button on the Max...was going about 65 on the highway turned off the OD and slammed it man i could feel it