Funny how this has grown to a 9-page thread. I recently came back from a germany, and whilst sitting on a tour bus, I kid you not that just about every single passenger vehicle I saw out there being driven was a manual.
We're not even talking about enthusiasts here, but instead everyday ppl, men and WOMEN, young and ELDERLY.
WHATSUP w/ YOU NORTH-AMERICANS??

 

10page thread now, and every post, all 136 of them counts and I'm taking in all of it. KAHBOOM just sells me on 5AT every time.. idk, DAMNIT, Why cant they be like the 300C SRT8 and give you just an auto so people like me dont need to go through this! (That car was actually considered and still is in some way)

 

At the risk of being crucified by the board, I gotta go with 5AT. Isn't the GTR going to be an automatic? If so then AT is all good.

 

I believe the GT-R will be offered in both AT and MT.

 

The GT-R will come in a automatic.... but it will likely be completely different from the G37 automatic. GT-R auto is more in like with DSG, F1 gearboxes and 7 gears, then the 5 gears and torque converter in the G37.

In other words, the GT-R automatic is more like the G37 manual but with 1 extra gear and without a foot-operated clutch.

 

The current times for 6mt's have poor launches. Car&Driver admitted it had trouble launching the car. From a roll, a 6mt will devour the 5AT.

In my test drive the G37 5AT felt sluggish in 3rd or above. It felt quick in 1 and 2, though.

You are right, it's not really about the performance, it is about the feel. I was just saying, let's not kid our selves, the 6mt is quicker and it is noticeable, especially in gears 3-6.

Get a 5AT cuz you prefer to ease of not having to shift over the direct feel of the 6MT, not because you think the 6MT isn't any faster.

 

Lambo paddles are nothing like G37 paddles. Show me the torque converter (aka Slush box) on the lambo.

The more I read in this thread the more I think it is so genius for car makers to start putting paddles on normal slushbox automatics. If people think what they are getting is what is in Ferraris and Lambos... wow that's totally smart marketing and sales work!

In reality, if you told the guy who designed the first automatic transmission that he could just have buttons for the driver to tell it when to upshift and downshift, you would have made him smile as you just saved him a bunch of work. Now, after trying for a long time to make them smart enough, we put paddles in there and people think they have clutchless-manual transmissions!

 

So then Edmunds, Automobile Mag, and Motor Trend must have all had poor launches as well... They all got similar times. The comparision between the AT and MT that I made was with Edmunds not Car and Driver.
In addition the trap speeds should be significantly faster on the 6MT than what has been reported thus far on the 5AT in order for the 6MT to be quicker and "noticeable, especially in gears 3-6". To say that the 6MT will "devour" a 5AT from a roll is unsubstantiated. I have raced too many 6MTs from a roll without being "devoured" even in my '03 5AT. In addition if Car and Driver got a poor launch (I don't remember reading that) then why not try again(?) C/D always posts their best acheived times- they often try multiple launches to get the best one.
With all due respect (not trying to be argumentative) I think that some who prefer the 6MT like to beleive that they have an advantage in acceleration but the truth of the matter is that all reports that we have seen thus far by professional drivers, with statistics to subtantiate their findings, prove otherwise. I would challenge you to show me numbers that indicate that the '08 6MT is significantly faster than the 5AT: How about a dyno chart(?) If you take a look back on this thread you will see dyno charts and stats showing otherwise.
If you are basing your opinion on the way the car felt when you drove it then many of your Hondas with VTEC are quicker than the G because many of them actually "feel" faster.

 

Sounds like you are starting to get irritated.

I've raced my share of 5ATs as well (1st gen). 3rd gear is see you later.

If the G37 6mt is only as fast as the G37 5AT I test drove, I'm going to be sorely disappointed because that makes it noticeably slower than my 06 6mt.

C&D specifically mentions the launch. The others didn't say. And, of the others, only Edmunds took the car back to their normal testing grounds. The rest drove it elsewhere so you cannot compare the numbers. The car Edmunds took home was a 5AT. It outran the 07 G35 Sedan 6mt. They have no cross reference to the new 08 G37 6mt at the same track. Nobody does, yet.

So yeah, I can't show you numbers on the 08 yet, because they do not exist. When they do exist, I'm confident they will show what I am feeling because I've never been wrong about this before in personal experience. We'll see, right? There's always a first time!

I'm not sure why you would bring up Dynos? What does that have to do with it?

If you compare gear ratios on the 5AT to the 6MT, in 08 G37 terms, it is clear that Infiniti shortened the gears on the 5AT to make it more competitive. 1st and 2nd in the 5AT are shorter than the 6MT, and they have the same final drive ratio. That means the 5AT will put more torque down to the wheels than the 6mt in those gears, reach redline sooner, shift at a lower mph. If that continues, the 5AT would cruise like a 6mt cruising around in 5th gear.

With only five gears in the 5AT instead of six in 6MT, the ratios MUST mean one of TWO things:

1. The car will be revving excessively high at cruising speeds because the gears are shorter than a 6mt but yet only 5 gears are present.

2. The car will reach a certain gear in which the personality will change from "quick" to "sluggish" as the short gears down low are compensated up high for cruising fuel economy.

From my experience, the reality is option 2 and the gear is 3rd. Is there a third, fourth, fifth, option I am not considering? I'm not trying to be argumentative either, it's just the facts don't support 5AT == 6mt performance, only non-comparable EARLY performance numbers, which I believe will correct themselves as more people own these cars and take them to the track.

To the original poster, are we threadjacking? Are you that concerned with relative performance or shall we be more focused on overall "feel" ?

 

I mentioned dynos because normally the AT is slower because of less power to the ground. In the dyno test of the new sedan with the same tranny as what is in the coupe there was only a difference of 2 HP at peak...

I think what you may be leaving out of your equation is the fact that the AT's torque converter is engaged in the upper gears to help make up for the 1 less gear that the MT has (thus the less direct feel). In addition, the car you test drove likely felt sluggish if
1) it wasn't broke in yet. The computer doesn't let the 5AT loose for the first few hundred to 1000 miles. The 6MTs computer is less restrictive early on. If you notice many of the cars tested by the mags had 2K sometimes 3K miles on them so the results were better.
2) YOu may have been driving in full AT mode.. there is a sigfinicant difference in acceleration using manual mode vs auto mode. In auto mode it shifts too early and it is not quite as quick or as direct (at full throttle) as when you shift yourself. In fact in full auto mode, unless you are flooring it, it shifts directly to 2nd gear at 5 MPH.

In most cases regarding AT vs MT your assessment holds true but the G has a superior AT tranny than most cars in the market.

Like I said the MT is no doubt a baddass ride and so is the AT. And as you said if down the road we find ot that the 6MT is much faster then I'll stand corrected.

 

Oh no man, you guys aren't thread jacking. Like I said, I'm taking value to all the post's here just as long as they differ between the two transmissions, that's what I need to learn. ALL Pro's and Con's for the two choices because like stated before, I cant just return this car like a iPod if I don't like it after my purchase.

I do appreciate all the responses, even tho some of you might get a little heated during it. Just remember guys, for the sake of keeping peace on the board, and friendships, debate if must... but don't get personal or take anything to heart k? I don't want my thread to break apart peace and friendships here k?

Again, Thanks for all the VERY GOOD responses

 

OK, I'll try to explain my logic beyond just how the car feels...

We've seen dynos showing similar WHP for 5AT and 6MT, so we know Infiniti has stopped handicapping the 5AT like in previous years. Also, the tires and wheels are now the same on a 5AT Sport as a 6MT, as is the final drive ratio. So, performance should come down to weight and gearing.

Gearing:

5AT ratios: 3.841, 2.352, 1.529, 1.00, 0.839
6MT ratios: 3.794, 2.324, 1.624, 1.271, 1.000, 0.794

Differences:
1st gear: 0.047 (1.2% 5AT)
2nd gear: 0.028 (1.2% 5AT)
3rd gear: 0.095 (5.6% 6MT)
4th gear: 0.271 (21.3% 6MT)
5th gear: 0.161 (16.1% 6MT)
6th gear: 0.045 5th vs 6th (5.4% 5AT cruising gears)

As you can see, the 5AT has an advantage in 1st gear and 2nd gear. This is no doubt designed to allow 5AT drivers to take off from a dig with similar performance to a 6MT (clutch drop). This results in the 0-60 times showing the 6MT only slightly faster. That doesn't add up, unless you factor in drive train loss, which is going to be slightly higher on the 5AT due to the torque converter and slightly faster shifts in the 6MT driven by a skilled driver.

In 3rd gear, the 6mt gains an advantage greater than the 5AT's 1st and 2nd gear advantages put together. In 4th gear, the 6MT gains an advantage greater than all advantages put together before that gear. It's obvious the 6MT will feel like a faster car at speeds above 2nd gear, from these numbers. Whether or not it shows in the numbers depends on what kind of race we're talking about. zero to top speed, the 6MT would demonstrate a very significant advantage. 0-35, I bet the 5AT would be a little faster. 0-60, they're almost even, 60-95, the 6MT would easily win. 0-100, very close again. 0-120, 6MT would easily win. So it all depends... the numbers are not as important as how the car responds to the gas pedal, IMO.

This is why you see 1/4 mile and 0-60 times that are very similar for the 5AT and the 6MT. Infiniti shortened the gears on the 5AT to help the 0-60 performance numbers. In the 1/4 mile, the 6MT has just selected 4th gear at 99mph while the 5AT is still in 3rd until 106mph. Even though the 6MT is now operating at a whopping 21% power multiplication advantage, both cars cross the line before it makes any real difference. However, if you were sitting in the cars, you would feel the 21% advantage in the 6MT... and if the race went on a little longer, the 6MT would start to eat at the 5AT even worse than it did in 3rd.

The 5AT also has a noticeably shorter cruising gear in 5th vs. 6th comparisons. This is done to keep the 5AT from feeling sluggish on the highway since the only option it would have if it needs to accelerate is to shift into 4th or 3rd gear, which would be a massive jump in RPMs. However, the 6MT can down shift into 5th and have the same ratio as the 5AT in 4th, or it can select 3rd which is a nice balance between the 5AT's 4th and 3rd gears. That is to say, at highway speeds (around here 70MPH), the 5AT will either under accelerate or rev really high and take off, whereas the 6MT can choose an aggressive but not frantic gear. Also, under normal cruising, the 5AT will burn more fuel running at the higher RPM due to the shorter cruising gear.

Weight is pretty much a wash. The 6MT has a 14lb weight advantage, similarly equipped. I don't expect that would be noticeable at all....

From my test drive, I was noticing how the car responds to the gas pedal at 2nd gear vs. 3rd gear at 4-5k rpm point. That's what I refer to as "how fast the car feels" and the 5AT I was driving felt almost as fast as my 06 6mt in 2nd gear at 5k rpms but much slower in 3rd at 5k rpms.

Hope that helps clarify what I've been trying to say...

 

OK.

FYI -- I was in full manual mode controlling the gears via the paddles.

 

Very nice write up and comparison. So in race conditions, 6MT obviously wins the battle, how about in every day, daily drive, 3k-3.5k shifts, 40mph speed limit roads... how do the two stack up?

 

In normal road conditions performance will be similar. Feel will be different. The 5AT is sluggish and inconsistent when shifting when compared to a good manual driver. It also selects 2nd gear really really early unless you are really on it, which makes the car feel slow. It does this to try to get better fuel economy overall, since 5th gear is suboptimal for economy. In manual mode, they will be more similar, with just slower/sloppier shifts in the 5AT compared to a skilled 6MT driver. Obviously the 5AT will be easier to deal with for the inexperienced or distracted driver, particularly at stop signs.

At highway speeds in top gear, the 5AT will be slightly more responsive to the gas pedal, at the expense of slightly less highway fuel economy. It will let the rpms swing up/down in response to the gas pedal without necessarily sending any more power to the wheels or engine breaking. The 6MT's direct connection will likely make it seem more response as highway speeds since the car will accelerate immediately in real-time with your foot. However, if you were to race the 5AT against the 6MT on the highway in 6th gear vs. 5the gear, the 5AT will win every single time.

Letting off the gas in the 5AT at lower RPMs will not slow the car down. It will at higher rpms (in my experience > 4k) because the computer locks the torque converter. At lower rpms, letting off the gas will return the engine to idle and the car will coast. Getting back on the gas will free-spin the engine until the torque converter engages. Again, think motorboat. When the revs rise enough, the torque converter will lock and at that point letting off the gas will slow the car down and getting back on the gas will immediately speed the car up. The 6MT will always slow down when off gas and respond immediately when you get back on the gas, unless you have pressed the clutch pedal. This behavior is the primary difference in "feel," performance issues completely set-aside. An torque-converter automatic has a delayed response to your driver inputs whereas the 6MT has no such thing. The automatic will in many cases "go limp" when you get off the gas whereas the 6MT will never do that.

They have pros/cons depending on your needs, so it is best to try them both and see which one your heart desires. When you test drive them, check these behaviors so you make sure you do not regret your choice.