i've been very tolerant with my new car so far, and i guess i will continue to be if your comments will indicate that i'm perhaps asking for too much. but with the quality of my drive getting comparable to an uhaul truck, and with a mild feeling of endangering my life a few times a day, i thought i could ask and may find good advice here.

so the car is a 2010 G37 with the sport package. there are 2 things happening, and for both i blame my gearbox. first is, when driving constant speed, at 35-40mph, my gearbox thinks it's cool to go all the way up to the 6th gear and reduce the revs to about 1500rpm. (how do i know it's 6th? a quick tap on the downshift pedal would step down a gear and show me 5 on the dashboard.) in this regime, if i smoothly press the gas pedal to accelerate, it takes about 3 to 4 seconds of gasping for power, until it finally steps down and i get some acceleration. (multiply the response time by 3 if driving uphill.) if i dont have the luxury to wait for that long, i have to press the gas pedal deeper: the response is probably 1-2 seconds, but the gearbox goes all the way down into 2nd, the engine revs up at 7000rpms, and all the moms around suddenly become overprotective with their kids. and of course i look like a moron, because i'm trying to get past a 1995 toyota tercel. things are a little improved if i drive in sport, but not by a lot.

the other thing happens when i have to slow down a little faster than normal. i press the brake, and if i dont need to go all the way down to a stop, at one point i release. in these situations, sometimes i get a quick few gears downshift, with a brief rev up to 5000-6000rpm. unfortunately this happened a few times right when i lifted the foot from the brake, and it kicked me a good 10ft in front - it felt like a leap. each time i guess i was lucky not being too close to the car in front, but it totally freaked me out. this behavior can be reproduced relatively easy in sport mode, but it occurs unpredictably in drive mode as well.

the rep from the local dealer told me that they have to see about the 1st one, and that the 2nd one is actually a feature - it's called "engine brake". (really?... i thought a brake was supposed to help you stop.) i took the car to their shop and said there is nothing wrong with the gearbox, and they "couldn't reproduce" what i was complaining about. i talked to the service manager, she offered to have my car driven by their probably most knowledgeable mechanic, and also offered me to drive another 2010 G37 convertible. their mechanic drove my car exaggeratedly careful; he definitely felt the lag of the gearbox, but he said it feels normal. he never even tried to accelerate deeper, to rev the engine all the way up, but he said it's normal when you suddenly ask for power. (which i agree with - but he never really wanted to see how uncomfortable a "normal" driving can get.) and he was able to reproduce that brake and jolt, but once again said it's normal. went on a ride with the other car - same spec and same mfg month as mine, except it didnt have the S package. this time me driving. smooth, efficient acceleration, good reprise, nice to work with. i could reproduce the "problem" during braking as well, but it felt totally different: instead of giving you a good jolt, that car was revving up and then down, and smoothly reducing the speed. i got the idea about what that thing was supposed to do, except that... on my car, it was done the wrong way. overall, i would have traded my car for the other one anytime. (they quickly asked me if i want them to make me an offer.)

so after this, i received a good lecture. i've been told that each car shifts differently, and the shifting is driven by the ecu. that there is no way to "tune" the ecu. that the ecu supposedly "learns" and "adapts" to the driver. (really? i would bet that switching gears so lazily is something that the ecu definitely couldn't have learned from me...) that there is no way to "reset" what the ecu has learned. and that (looking at the part numbers) the ecu on the non-S is different than the one on the S, so the non-S is smoother and cool, while the S is... well, normal.

personally i've never driven a car with such a poor performing gearbox in my whole life. if i compare with the other infiniti's that i drove (and i drove 5 or 6 of their loaners, since i had my car in for repairs a few times so far), my sporty convertible performance sucks. this is obvious for me and for pretty much anybody else that drove it. yet i am told by an authorized dealer that it's the way it is, and i am offered examples of all sorts of prizes for performance that infiniti obtained over the years. i didnt argue with those guys at all, because i first wanted to clarify if i suck, my car sucks, or the G convertible series as a whole sucks. and i understand that asking on an enthusiasts forum a question like "hey everybody, does your car suck as well?" is not exactly a nice thing to do. but what would be your advice in my situation?...

thanks everybody.

You're describing two reoccurances of something that happens and is a factory standard.

First being, the car acceleration. Yes the car is in 6th at 40mph. This is to save gas. Secondly, the car does take a bit to down shift, and you will be draggin a** in this gear cause its so high and your rpms are so low. You should be proud you're in 6th at 40mph.

The car does fly into netural when you press the brake. Yes it is kind of considered engine braking. However, it is a feature of the transmission.

The same car, or different series of a G will do these exact same two things.

My 37 sport coupe doesn't do it as bad when I hit the brake (for whatever reason?) but the sedans do it really bad I have noticed with these damn loaners. Like the one I have now. Omfg, don't hit the brakes to close cause you go flying forward. It is an 06.

And no you won't have any umph in 6th gear at 40mph. Switch it to DS mode, down shift, and fly past them.

Sorry man, but what they are telling you is exactly whats going on. You have drivin either a Journey or a Base, and said it doesn't have that jolt when applying the brakes. Yours is just different. Trade it.

I understand your concern. I do not like that feature either when you apply the brakes. That is why I am glad I sourced through a lot of G's, and found a sport coupe that was perfect.

I think the 'S' auto is a hoot! You have five ways to shift it! I often use the sport mode in town to get more rapid up and down shifts in traffic. I use regular drive if I'm just moving along and want the best milage. I don't use the forward and back shift lever in sport.

I use the paddles in traffic in normal mode for temporary downshifts to accelerate. I use the paddles in normal mode going up and down curvy steep mountains. I'll use sport on curvy, relatively flat, roads.

I seldom use the paddles in sport as the trans stays in the gear selected. I might forget to shift. I find having an ultra-close gear selection, seven speeds, a bit much. Easy to hit redline. Maybe I'd use that on a track or in autocross.

Maybe you could use the sport manual mode in town. Then you could control acceleration and deceleration. Just remember to watch that tachometer.

#1 sounds like a learning issue with the adaptive trans. #2 sounds like a real problem that could in fact be rather dangerous!

I have a manual trans so I cant comment on the specific reactions of you car but I can tell you that Infiniti has adaptive transmissions which will "learn" your driving style and adapt to it. For example, if you like to take off from the line quickly, the car's trans will assume and anticiapte that each launch will be a rapid start and react accordingly...

There are ways to have the trans "re-learn" existing habits by performing a reset of the ECU. If you are unhappy with the "features" that you are experiencing and that yourr dealer describes, I would start there.
Good luck!
-B

i'm not shy of switching gears manually. my previous car was a honda s2000 (shifting was a joy), and before that i had an audi a4 with cvt (no shifting whatsoever). i'm not really the kind of cry baby either. i probably should have stated the reason why i ask my question: i wonder if i should just resign and say "oh well", or should i insist in front of my dealer that my gearbox needs a fix. because, there's no way to sugar-coat it, my car drives bad.

so to summarize what i have so far. i guess fukin tells me most of the G's are the same, and you have to cherry-pick when you buy. but regarding the pride of 6th gear @ 40mph... mmno. i dont feel any pride. it would be like the pride of riding a donkey and paying for a racing horse. and if infiniti needed this to get a better mileage, i.e. 14.8mpg, i find it pathetic. (fukin, this is nothing personal, and i genuinely appreciate your answer because it does answer my questions, but you and i dont feel the same way about this topic.) EdSac - i drive my car pretty much the same. but i think the manual shifting option on an auto gearbox should be just that - an option. i find myself tapping, or tap-tapping, the left paddle, every time i need to accelerate. this is just to get the same response that i have from my subaru suv. i think it's wrong, but that's just me. everybody else seems to do the same, but they dont complain. bschurr - i agree with you in what refers to taking off from a full stop. that is, indeed, a good feeling on the g37s. but this example that you're giving me is the only one that i heard preached over and over again. i dont think this "learning" legend applies to any *other* gearbox operation, or if it does, it certainly learns the opposite thing than the one i like to do. besides, the dealer told me last week that there's no way to "reset" whatever the ecu has learned.

let's put it this way. it looks like what i noticed, and i'm not thrilled with, is a characteristic of all the series, or more probably of this particular gearbox. so may i ask: are you guys happy with the performance? is your car, from this perspective only, living to your expectations? i dont have a problem admitting that i may be pickier than the other ones. but am i the only one unhappy?

i find it easy to explain everything as an overdesign that went wrong (in my world of software engineering this is called "feature creeping"). think about the dashboard that has buttons on a non-touch-screen display, some of them with text and some of them with icons. remember the usb that doesnt charge your phone, or crashes the dashboard if certain songs on the ipod contains certain characters in the title. or the bluetooth that wouldnt pair because the top is open (yet it would answer the phone for a horrific conversation). or consider that puzzling feature that wont let you pop the trunk open if the engine is on (but sorry, no turn off the headlights when the engine is off). now think about the same engineers designing the ecu that controls the gearbox. see what i mean?...

i guess i'm going to have to live with what i have, and hope that i wont be thrown in the car in front by one of those driving habits my gearbox picked up from me. i'm thinking this could, at one time, turn into a clusterf* like the sudden acceleration on the toyotas, and at the same time i hope not. meanwhile, at least, i'l take this opportunity to warn everyone about a potential danger when braking.

edit: bschurr... nice, um, other car, man

The loaner I just had was a total piece of s***. If beating on a car like that, driving it to its max all the time, and then destroying the gearbox, made the car drive, and feel like that. I would of never bought a f*** infiniti.

Buddy, if you are having a strong problem with the gearbox, and think it is crazy to just sit there and feel like you have purchased something very expensive to only not be satisfied, you need to correct it, now.

The gearbox in my loaner was almost unbareable. It made me feel so unsafe when coming to a stop, and typically, I like to shove the car into drive, from reverse when backing up. When I did this in my loaner, THE CAR BUCKED UNCONTROLABLY. I couldn't believe it. Stepping on the brake SLUNG the car forward at a scary pace, and it felt like the car had been in the floor so many times, it didnt have anything left.

This car did not have a lot of miles on it, and was an 2006 G37 model. Many people ragged it out, and if your car felt anything close to like what I just described, please return it, or make them fix it.

If you bought a used car, you should of really tested most of the infiniti's on the lot. Just have to let the dealer understand they are selling you a product right, do their best. Once they know your job, its pretty easy to drive everything on the lot. I went through 4 before I made my purchase of the class of car I was interested in (coupe).

I'm gonna ask around about this.

I have a feeling I know what the OP is complaining about, but I don't know the cause... I just know that I had similar frustrations with my 1st-gen G35 over throttle tip-in, which took FOREVER to resolve.

BTW, your dealer is wrong on the ECU "learning" - it CAN be reset. I believe it's as simple as disconnecting the battery overnight.

fukin - no, i bought the car new. however i bought it from a dealer about 50mi from where i live, and didnt test-drive it before. for the last 10 years i bought cars like that - test drove at the local dealer then order the car from wherever i could find it with the accessories i wanted and for the price i wanted. i've never felt a difference between what i test drove and what i got. i guess i did this one time too many. i'm more on the moderate side of the driving style, and i'm not a tuner or a modder or the kind of guy that falls in love with his car. i doubt my driving style broke the gearbox - if it would, i would continue the same way, maybe even harder, until i would break it completely. (or maybe not )

AZhitman - good thing your dealer acknowledged that as a problem and as a life-threatening issue. my dealer treated it as "normal" and as a "feature". and i know resetting the ECU can be done, and what they told me is BS. but most of what they tell me regarding a lot of other issues was BS as well, and i'm tired of telling them i have a hard time believing what they say.

i'm taking it in tomorrow again for a coulpe of other things (noises from the back again, plus something dangling underneath the car) and i will bring up the gearbox problems once more. i'll let you know how this develops.

well, unhappy to say that i dont even had the chance to bring up the gearbox issue with my dealer anymore. they didnt want to say anything else than "all the 2010 convertibles do the same", and they didnt even want to make any paperwork about the fact that i notified them. so if i get into an accident because of that, there will be no record that i even tried to do something about it. way to go, infiniti dealer.

meanwhile i had to take the car to the shop 2 more times for "fixing" sounds from the top and trunk area. i guess they got bored of trying that too, because the last time the mechanic that drove with me pretended he cannot hear anything. yeah right. they took the car and gave it back to me after spraying some oily stuff on the rubber seals between the top segments. whatever. i'm going to have to go to another dealer, which is going to suck because it's way further.

by the way, do i risk damaging the gearbox even worse if i shift it to neutral whenever i need to brake hard? and then if i put it back in drive while still moving? i never tried, i assume the first one would be ok (if it would work at all), but i have a hard time thinking what would happen if i try neutral-to-drive while car is moving.