I test drove my car (G37 Journey 7A) with a tech expert from Infiniti. The expert acknowledges the low speed bogging problems, but says there is no solution yet.

 

I must also add that the low speed bogging and erratic shifting problems may not be obvious in typical US driving, because you don't experience the exasperating daily stop-n-go situation as we do in Beijing. As I mentioned earlier, continuous acceleration to 60mph or above does not seem to show any problems. The car does like to drive fast and handles well when fast. But when it slows down to under 25mph, it gets so nervous and hesitant that it scares me often. Since the problem is on the erratic and unpredictable side, I believe you will never get used to it no matter how much you drive it. SAD!

 

We do plenty of slow driving over here! I keep thinking about your comment where you say your car is pulling 1200 RPM in 6th gear. I've notice that mine really doesn't let the engine speed go below 1500 RFP in almost any situation except idle. I'm beginning to think your throttle might need to be tweaked back to specs. That would definitely smooth things out and stop most of the bucking. I don't know how this fly by wire throttle works, but I know that modern cars balance the throttle position with the transmission, etc., so if your throttle baseline is wrong, you're going to have driveability issues.

 

Thanks for the update Beijing. I'm getting ready to leave the country next week for a month. When I get back, I'll have infinity check out the car and advise at that time.

 

I've now had my G37x for about four days, during which I've done a fair amount of driving both in traffic and on open roads. One thing I notice about the 7AT is it tends to shift pretty much as I would if I were driving a manual transmission. It's kind of strange to have an automatic acting like that, but honestly I really like it.

I am still waiting to see how it does in a no-kidding Washington DC traffic jam, but I've driven in some stop-and-go already and so far have had no issues with rough downshifts, and after reading this message thread I have been very aware of what the 7AT is doing.

 

Give DS a try when you're feeling spirited

 

Been there, done that

 

DS mode has no obvious effects in gearing and RPM when using mild throttle in low speed driving. But shifting gears manually under DS mode helps a bit.

 

the g37 transmission should downshift on DS. the transmission downshifts on D when it should not. the downshift of the transmission in D appears to be a defect as an automatic usually has a seamless , unnoticable downshift. this car does not . at 40 the car down shifts , slightly ,around 30 its more pronounced, at 20 the car downshifts violently, almost slowing the car to a crawl. to avoid this i have to put the car in neutral to get a smooth slowdown. currently there is no fix for this. i dont believe the engineeers could want to have purposely designed this type of ride for the D mode, when the DS mode is there to give that type of ride. are many of you experiencing the same type of decelleration problem in the D mode?

 

i agree. i am experiencing the same exact problem. i believe its a design defect as it does this in D and DS. its as if the car is driving as a stick with a harsh slowdown. this is not how an automatic should drive. i never use the DS mode and would never have bought this car if i had realized this problem during the test drive. the dealer didnt mention this feature. if they did i would have passed. i regret my purchase and really dislike this new 7 speed transmission. i hope the engineers see these posts and can fix this defect soon.

 

It's a devil at low speeds. The car feels lazy and erratic in stop-n-go traffic. The driver is is left nervous and fearful. I'm keeping my car garaged and looking for a buyer. Defintely the engineers at Infiniti failed to do a reasonable job to program the transmission and engine. The saddest part is that this car is getting so many positive reviews from Edmunds and such. I went through most of the reviews before purchasing this car, which costs about USD80K in Beijing. Now I feel cheated and misled.

 

Maybe the way this car downshifts just fits with how I drive, but I have no problems with it at all. Yes, I can feel the downshift at 20 MPH but it is in no way jarring and just induces the kind of engine braking I would do myself if it were a manual transmission (as I have done with the manual transmission cars I owned for the 20 years before I got my G37).

I've had my G37 for a week and a half, driven it in all sorts of conditions (dry, wet, on surface roads, on the highway, no traffic, moderate traffic, hellish Washington DC traffic) and so far I'm entirely happy with it.

 

So does everybody reporting this problem have the RWD? ie: no AWD?

I wonder if this is why only some are seeing this problem much worse.

I bet most non-AWD cars are with manual sticks?

 

I think this problem is way over blown, the gear ratio difference is huge at low gear.

 

I agree. The first gear ratio number is very high. Picture below is taken from the Coupe forum. The 7AT would have to keep it in 2nd during slowing down to a complete stop to prevent the jerkiness.