2008G-Man

If you are in DS mode, the hard downshift is supposed to happen, it's called rev matching. Also, the way you used to do it in a manual is not the proper way. You shouldn't slam your car into the lower gear at high RPM's but using the transmission to help slow down is the proper way (not going into neutral), except when going to a complete stop, don't go into first, go from 3-2-clutch in, brakes & stop. Your way wears out brakes.

gatchek

No, I wasn't in talking about the rev matching, I understand what that is and when its supposed to kick in.

I was referring about coming to a stop, when I said that I would shift into neutral. Sorry if I didn't clarify. In my standard, I always just shifted into neutral and coasted to a stop. I never slammed it into a lower gear. If I was to downshift when racing, I would rev match before dropping down a gear.

When downshifting to a stop, your RMPs are higher than idle. It is my belief that the downshifting method eats up more gas, since you're at a RPM higher than idle. Yes, it does eat through more brakes, but I'm replacing them once every 40-50K miles, meanwhile... I'm filling my tank up every week. I think you'll pay more money in gas than brake pads... just my opinion of course... not back by any proof.

Getting back to the topic at hand... the transmission update DID help the harsh downshifting when coming to a stop. Of course it still rev matches while the drive selector **** is in "SPORT" mode. I wouldn't say that it "drastically" changed the transmission, but it has help smooth it out. It ran great before, and it just runs even better now.

Almatti

I recently had a new 2014 Q50 as a loaner form my M37X. I noticed that the drivetrain is better, more responsive. It is the same: 3.7L engine/ 7AT. I liked it, Personal Performance sport sedan. If it had just a little more room, I would seriously consider the car. The M is more luxurious, a very attractive interior, but less sporty (although not a slouch by any means). One lesson: the new cars offer the Touch Screen dynamics. That takes getting used to.

gatchek

Can you elaborate on the touch screen dynamics? or maybe provide a link? I'm assuming that's Infiniti's latest touchscreen technology.....

Almatti

Gatchek, check the website and utube video reviews. The touch screen has more menus to go thru. Thank goodness Infiniti kept climate control buttons for easy access in addition to touchscreen controls. Total touchscreen controls like on the Lincoln MKZ turned me off. A key reason I didn't go in that direction when considering a car to replace my 2010 G37x last June.

Hedgehog25

I've been driving my 2012 M37x for the last few days, and I'm wondering if my particular vehicle needs the latest transmission software update. Don't get me wrong -- it drives great, but I've been noticing that when accelerating from a complete stop, it feels like the transmission quickly shifts about 1-2 seconds after I first start moving (it almost feels as if something "bumps" underneath). It's a very minor sensation, but is the transmission supposed to shift after just 1-2 seconds of gradual acceleration, when the car has barely made it "up to speed" (I'm thinking 10-12 MPH at the most)?

Also, this phenomenon is accompanied by what almost seems to be a brief period of lag as the car accelerates. It almost feels as if there's something under the car that wants to prevent it from accelerating for a few brief seconds (and this is only noticeable when accelerating from a dead stop).

Does anyone know if the above-noted observations are indicative of normal transmission functioning, or is the car likely not updated with the latest transmission software version? The thing is, the closest Infiniti dealership is ~100 miles away, so it's not really feasible to simply visit the dealership during the next few days.

Also, one other thing... the other day, I was traveling down a two-lane road at ~60 MPH when the doofus in front of me abruptly braked to turn left. I was driving in "Sport" mode at the time and basically had to slam on the brakes to almost instantaneously decelerate from 60 to 0 MPH. When I did this, it almost felt like something... banged (?) underneath the car. I'm not sure if it was the brakes or the transmission, though. My question is, is it bad to stop abruptly like this while driving in Sport mode? Can a one-time hard-braking like that mechanically damage the transmission?

Thanks...

tech37

Sometimes the downshift when in sport mode and braking to a complete stop will cause a hard downshift. As for the reprogramming issue...this is a funny transmission...doesn't like low rpms...but it might take the car sometime to learn your driving habits. One way to see if you need a reflash is to set the cruse using the ICC (full range CC) and see if the car acts like it's surging and/or confused....watch the Tach...and have the owner verify at your next service....

Hedgehog25

Thanks. I'll try-out the ICC function when I'm driving tomorrow and see what happens.

Not sure what you mean about having the owner verify at my next service... ? I am the owner of the car now.

BTW, are the hard downshifts (like what I experienced when braking abruptly while driving in Sport mode) bad for the transmission, in a mechanical sense? Should I just stick to driving in Standard mode?

tech37

My mistake...I meant dealer...I use sport mode but try not to use it when I know I will be in an area where I might have to slow down

Hedgehog25

No problem LOL. I think I will lay off driving in Sport mode unless I know I'll be on an open highway for at least a few minutes. I just hope that the harsh, sudden downshift I experienced the other day when braking suddenly didn't damage one of the gears.

Also, I'm not sure if this is relevant, but I've been driving the car for almost a week now, and the average MPG still reads "15.2," which is exactly the same reading that was displayed the day the car was delivered. Does the average MPG calculator need to be reset, or am I really driving the car in a manner that results in it getting such lackluster gas mileage?

tech37

You need to reset it...and you have to do both separately....the LCD in the gauge cluster and the one on the navi screen are not linked....why? idk but whatever...lol

You didn't damage the gears....what you probably felt was the TCM trying to hold the gear as long as possible...then rev match for the downshift...causing the confusion and hard shift...a lil hard on the clutches maybe but no gear damage.

Hedgehog25

Thanks for the info. Just out of curiosity, do you know how many times I'd have to abruptly brake and hear the loud "bang" to actually cause damage to the clutch? I definitely don't plan on doing that often, but I'm just curious.

Also, last night while driving home in Sport mode, I made a sharp turn to get on an exit ramp and began slowing down by letting off the gas (not really braking), and even though the car's speed was naturally slowing down, the transmission felt like it was trying to hold the car in a certain gear. I guess this would be the rev-matching? You can tell this is my first sports car, LOL.

tech37

Sports mode gives you rev matching when you downshift but it also holds gears longer to keep your RPMs in the power band.

With AWD you have so many more drivetrain components....lol but I would try to avoid the abrupt braking in sports mode until you can get the dealer to take a look at it.

Hedgehog25

Had another interesting experience today. I live on a quiet 2-lane road, so on my way home, I decided to have some fun with the car in Sport mode when I turned onto my road. I accelerated up to about 70 mph, and as I started going down a steep hill, I started to gently brake. When I did so, the car started slowing down (as it should), but the RPMs briefly shot up as I was slowing, and around the same time, the engine revved/growled pretty loudly. I actually wondered if I had just passed a dump truck or something, but then I realized it had been the car that had made the noise. But even though the RPMs briefly shot up for a second and the engine roared, the car didn't actually accelerate (which is a good thing since I was braking and slowing down).

Do you know if this is just a normal behavior for the car? Is it supposed to briefly (for 1-2 seconds) increase RPMs and rev the engine when braking while going down a hill after traveling at fast-ish speeds?

2008G-Man

Dude ... you are over thinking things. Drive the car, enjoy it and let it go man :-)