I read a bunch of threads on the 5AT MM modes and didn't find the answer to this question. I was messing around with the MM mode which I rarely use and found that leaving the gear selector in 5th for instance does not prevent the transmission from selecting a lower gear. Is this a correct assumption? I know the 5AT will not automatically upshift in MM mode (which even our 2006 Maxima does...) but does it downshift? I know with a true manual transmission driving at slow speeds in high gear can lug the engine and even burn the clutch. How does the 5AT handle this in MM mode?

 

All autos will automatically down/upshift.

Put it this way, if you are in MM and come to a stop, you aren't starting out in 5th!

In MM, the gear shown on the dash represents the highest gear it will automatically shift into. ie... let's say you select 3rd. From a stop, it will start out in 1st and auto shift into 2nd and 3rd. But will stay in 3rd until you shift.

 

Ok there you go, thats exactly what I thought. So I can drive around all day with 3rd gear selected and it will basically use gears 1, 2, and 3? I believe this changed with the 05-06 but I hate how the 03-04 tranny doesn't automatically upshift when you hit redline. Our 2006 Maxima does it in MM mode.

 

YOu are correct. In the 05+ autos putting it in MM at a light will put the tranny into 1st and you have to shift for every gear.

But even the 05+ won't shift out of the gear at redline if you are in MM

 

I have 04.5

I can redline in any given gear and it will not upshift

in any gear higher than 3rd it will downshift to 3rd when the rpms get low enough (but I've never noticed what that rmp is.

in 2nd or 3rd it will not downshift on its own until I'm well under 1K rmp (around 800 on tach, but tach is about 150 off actual rmp).

Its a b!tch trying to get exit speed out of tight corners... on the street its easy - but I raced a road course this weekend and found how trying it is. (MT is a must for road racing, but that's a given anyway).

 

it wouldnt be a truely "manual mode" if it shifted at red line... i hate cars that do that.

 

I dunno about pre-05s, but my 05 shifts like this.

If you're at highway speeds and in 5th but auto mode, when you put it into mm, it'll go into 4th.
You can redline in every gear and the car won't shift up.
The car will shift automatically from 5 to 4 to 3 and then to 1 as you decelerate. It'll never automatically downshift to 2.

 

it will for a split second sometimes, other times it goes from 3 straight to 1...it depends how hard you are braking

but the answer is yes, it will down shift automatically

 

its best used when you want a burst of speed and you knock it over and then kick it to 3rd and hit the throttle. hammers out some power! i love it!

 

its based on rpms - no matter how hard you are braking (at least in my car)... see a few posts above

 

I have an 05 auto and mine works just like badtziscool explained


However I had an older sedan as a loaner once and it did not down shift until you brought the car to an end. Dunno if it had a tranny prollems or what but that's what it did. I found it kinda strange cuz I was not use to it.

So as far as 05 model. Transmission will automatically downshift if your engine RPM is dropping but it will not upshift.

 

so, im assuming its a bad thing if you downshift while driving or coming to a stop?

 

no its called engine braking... its the same thing truckers do to slow down their huge loads quickly... that loud drone you hear coming from a truck slowing down is the tranny engine braking.

the G35 has a great sound when engine braking! Plus it saves your brakes.

if you look in your owners manual every gear has a max speed... and they recommend a use for each gear, and even use the term "engine braking"

engine braking is using the tranny to slow the car down by down shifting early.

example say you are driving 60mph in 5th gear... and you see that stop sign coming up ahead. If you drop the car to 3rd gear and release the accelerator... the car will easily slow to 40mph then drop it again to 2nd and you will drop another 20 mph... all with out hitting your brakes. then you finally hit the brakes as the tranny down shifts to 1st for you. (or you can go to first earlier too)

my very conservative rules of thumb for engine braking

above 100 down shift to 4th
above 50 down shift to 3rd
50 mph and below down shift to 2nd

i never down shift to first in general

 

so couldnt that potentially mess up ur tranny?