4DOORFUN

In an effort to boost fuel economy, Infiniti programmed the car to upshift as quickly as possible. The 7AT strives to get into the highest gear possible at all times. That's pretty normal for an AT. The car is programmed to automatically downshift to lower gears as you slow down so you have power on tap should you decide to hit the throttle. This is also normal for an AT. My personal opinion after test driving the car is that the 7AT programming does not match up well with the VQ motor. There's not enough low end torque produced and therefore the 7AT cannot hold its current gear very long during city driving. The 7AT feels like it is constantly hunting for gears unless you are crusing on the highway. Infiniti can reprogram the 7AT not to upshift so quickly, but then fuel economy will suffer and that will hurts sales figures. The car G35 was already heavily critized for poor fuel economy. That's why they added the 7AT and claimed slightly improved EPA ratings for 2009. Unfortuately, the 7AT programming does not match well with the poor low end torque. The 5AT gear spacing is broader and the need to downshift occurs less often.

I would not be surprised to see a turbocharged motor hit the Infiniti brand in the near future. Modest displacement turbocharged motors produce good power and fuel economy (i.e. BMW 335i).

Mike

iTrader: (1)

There is an alternate program. It's called DS mode.

4DOORFUN

I agree that DS mode is an alternate program, but not exactly what I’d be looking for. DS mode kills fuel economy and keeps the motor buzzing. If the motor had more low end torque, that would eliminate the need for DS mode and all the gear hunting that some owners are beginning to report. I just prefer more low end torque on my performance cars. I don’t like having to wind out the motor every time I want decent power.

Mike

iTrader: (1)

DS mode shifts based on throttle position and driver adaptation. It will continue to shift up gears, albeit reluctantly. However, it won't shift into top gear. Rule of thumb is that if your driving habits and throttle use stay the same, it'll keep the engine 1000-2000rpm higher than in D.

How long have you owned your G? The transmission does hunt when you first get the car, but if you are the only driver of the car, then it will adapt to you, and the hunting will go away.

4DOORFUN

I don't own the car. I only test drove it. It's a wonderful car and if the transmission truly adapts to the driver, that's good. I just doubt the need for seven speeds. It feels like a properly spaced 5AT would do just fine. It’s not like the
5AT had any problems.

If I bought a G and had to get an AT, I think I would pick up a used 2007 RWD model. The 7AT is lot of hype. No need for that many gears. Someone already said it, and I agree. I wish they would have just lightened up the existing G35 Sedan a bit. Fuel economy and overall performance would increase with less curb weight. Unfortunately, curb weight does not sell cars. Most buyers only care about horsepower.

G37xS

What you want is a turbo car. like a 335 maybe, with high torque on low RPM. A high reving engine is different in performance and driving capability. Just like the new high reving M3 wherein they have the same torque rating as the 335. As what was said in the M3Post, the 335 has instant but short gratifications as compared to the M3 with a slow and long lasting ejacul...

Herkypilot

I happen to like the 7 AT and what you are talking about with the shift pattern is adjustable with flash programming. Nobody has complained about 6th & 7th going down the highway.

I also happen to like the 30 MPG I get on the highway instead of the 20 MPG I've been reading that the 5 AT gets!

Reno-ID-Doc

I have to respectfully disagree with that 7AT is just mere hype. There is sound mechanical engineering concept to efficient transmission having more gear selections. In theory, a continuous variable transmission (CVT) would attain the highest efficiency.

What limits current trends in the mechanical evolution of the AT having more gears would be A) cost of production & affordability B) increase in moving parts & its inherent issues C) adapting flexible programs that are required in managing increasing complexity of optimum shifting D) affordable but higher special metal alloy to allow stronger but smaller moving parts E) ultimately market forces feasibility (the ability of the purchaser to accept new technology as it sees fit). As one can see, there will be a limit on number of gears for an era as imposed by current technology, regional economy, and utility. Most motorcycles with MT 6-speed standard now had to start somewhere, and in the past, as more gears where crammed into the small gearbox of a motorbike, someone has to ponder whether this is just hype or useful technology.

How Nissan-Infiniti was able to trickle down this new technology to G37 without bumping up the $ price tag too much is an amazing feat on its own. Somewhere down the road, people will see some true fuel cost savings translating from more efficient transmissions.

PeterUbers

iTrader: (1)

Good post. The Lexus LS460 has an 8-spd transmission i think, I would love to get into one of those for test drive to see how it drives -- I imagine Lexus figured a way to make it silky smooth as they find a way to do most things with their vehicles. To date, the 8spd auto is the most gears in a metal box that I'm aware of.

RotaryRevn

Here's an update, my car still has 1700 miles and still does it. I took it to the Infinity dealership and the tech felt the problem. He checked for any flash upgrades and there is none at this time. The main office that releases these updates said it's "under investigation". I questioned the tech on what that ment and he said Infinity is aware of the problem but they dont have a fix for it yet. I hope they get one soon. I still feel that if I was aware of this problem prior to buying the car, I would not of bought it. I'd return the car today if they would let me and give me a full refund.

gugarci

Here are my thoughts and experience on this issue. My 09 G37S Sedan now has 814 miles. I'll start by saying that the 5 speed on my 08xS did not have this issue and overall was smoother to drive at slow speeds. Having said that I'm beginning to get used to this issue. It's definitely the downshift from about 20-25 MPH's. And You feel it most when slowing down in bumper to bumper traffic or coming to a stop at light in city traffic.

What I've been doing to remedy this situation is to apply my breaks very gently. I'm usually light on the brakes anyway unless I'm driving hard. The problem is the downshift makes the car feel like it's coming to an abrupt stop, But it's not. It does give off that illusion though. So a person that's hard on the brakes, like my wife, will apply more pressure during the downshift and will cause the car to brake very abruptly.

Having said that if there's a TSB release for this issue I'm hoping it fixes the problem in D mode only. I don't want to loose any of of the sporting nature of the gearbox. Otherwise I will pass on the TSB.

Silver37

I find that braking moderate to light above the shift speed, then backing off to super light has really smoothed things out. After doing this many times, the 3-2 downshift has gotten smoother - even when I'm not using the two step approach. I'd still like to see a fix from Infiniti.

DownstairsDave

I will have to disagree as well:

1. Having more possible gear selections will increase fuel economy.
2. From what I have heard, the new engine (mainly the addition of VVEL) was the main reason for increased fuel economy.
3. Of course the 5AT gear spacing is broader. There are less gears. This would require MORE torque from the engine when compared with the 7AT.
4. According to Edmunds.com, the BMW 335i with xDrive actually has WORSE fuel economy than the G37x Sedan (19 mpg vs 20 mpg)

Edit: Fuel economy for sedans is identical to coupe versions: BMW 19 Infiniti 20

timcodon

I completely agreed with "RotaryRevn"'s 'I still feel that if I was aware of this problem prior to buying the car, I would not of bought it. I'd return the car today if they would let me and give me a full refund'.

I too felt the exact same way. I love this car just about everything, EXCEPT this weird downshift issue. It seems to hunt for the right lower gears at slow speed. And at time to apply brakes to stop the car, I have to played some tricks, such as apply the brake gently. But then, sometimes, I really needed to aplly quick brake for some tight situation, I found the car stopped too abruptly, both by the brakes, and by the downshift issue.

My car now has 2600 miles, and I thought it would go away by now. It has decreased some, but it's still there.

I REALLY would like INfiniti to read this blog, loud & clear, and get thru with their INVESTIGATION, and fix this issue. It truely bothered me a lot, as I'm thinking spending almost $40k, and having to deal with this frustration issue...

I'm waiting for the day Inifiniti has software update to the "D" mode, as it acts like the "DS" mode in some other cars.

Ginger

People, stop complaining. You bought a Sports Sedan, you should have test driven it before you bought it and if you did, it did the same thing then. You shouldn't expect its characteristics to change with age and miles too much. I have over 20k miles on my '09 and it doesn't go away. It's just the car letting you know what's going on, like all sports oriented cars should. Pretty good from an auto box in my opinion.