superjer2000

I currently have two G37x in my garage. I took over the lease on a 2009 with 28000km a couple of months ago and then I was offered the opportunity to purchase a new G at an amazing VPP discount. So I ended up purchasing a 2010 G37x with the Sport Package (Canada -> 18" wheels and Dunlop tires).

The 2009 seemed to handle like it was on rails. If you took a turn at a quick clip, the entire car seemed to really hunker down and stick to the road. This was with both the OEM All season tires and Primacy Alpin PA3 winters.

The 2010 (with only 700km to date) isn't the same so far. With the stock Dunlops the car tramlines a lot (which I now know from these forums is a common complaint with those tires) but when I take a corner fast, it seems like the back end isn't, for lack of a better description, staying down. It seems like it is swaying loose, if you will. I thought it might just be the tires, but I put on winters today (Blizzak WS70s (admittedly not performance winters, but the Dunlops should have been pretty sporty) and I get the same sensation where it feels like the back end is going to break loose. (I am not driving at extreme speeds either, just somewhat spirited driving).

So after that long intro, my question is: Could this be part of the breaking in period of the car? (I would assume not, and that things should be tighter now than they ever will be again). Could there be a problem with a sway bar on my new 2010? Any other thoughts or advice? I'll be honest, at this point, my 2009 is way funner to drive but I really want to keep the 2010.

Thanks for any help or advice.

maxfinity

My car does this but I think its more so because of my inexperience with rear wheel drive cars. Had to learn to keep pressure on the pedal during spirited driving because if i layoff the rear wheels begin to slip. Maybe the tires need to be broken in. I hear some tires don't perform at best until broken in.

6mtg37s

iTrader: (1)

Yea tires might need to break in. Gs are usually very *** happy cars so this is no suprise! Its fun oversteering tho.

harp00n

try to put RWD rear sway, it might help

zmzmzm

I would guess it's the tires, although if your car was out of alignment that might cause handling problems too. I'm in Ottawa and have snow tires on mine, which fixed it for me (a 6mt rwd).

-Mark

Icerider2001

The problem is purely in the Dunlops! Those tires just don't grip as far as I'm concerned, and they ride like their made of plastic (rubber compound is simply too hard). As for getting the same feeling of being tail happy from the Blizzak's too; it's just because their not even the same class of tire and fall at the opposite end of the spectrum. The compounds of winter tires are very soft to begin with (designed to perform specifically at lower operating temperatures), thus they don't take kindly to being driven aggressively.

da mayor

iTrader: (2)

i just switched to falken ziex 512's adn grip a lot better than the dunlops

superjer2000

Thanks everyone. I think it is the tires as well. I completely agree with Iceriders' comments that the Dunlops don't grip and the Blizzaks are too soft. I'm hoping that the Dunlops will come into their own when I put them back on this summer.

I want to say that this forum is great - I have already searched and found a lot of information answering a ton of questions I have had since I got the G. This is probably one of the most helpful auto forums I have come across.

dkmura

What you're sensing is the proper operation of the Infiniti AWD system. It's set up to provide 100% RWD bias during normal operation and only transfers power to the fronts when it detects rear slip angles developing. I particularly notice this quality in my G37xS sedan in the snow. I also have the Dunlop SportMaxx tires and they hook up just after turn-in. But do a classic skidpad run in a parking lot and you'll notice you can hold the G in a slight oversteering attitude with just the throttle.

This RWD bias is something I've noticed in testing the 2010 and 2011 G sedans as well. I don't believe there's much, if any difference, in this regard. Driving something like an Audi S4 with full-time AWD has a more "locked-in" feel to it, since all four wheels are constantly in AWD mode. I much prefer the more sporting feel of the Infiniti system and the ability to rotate the car slightly on turn-in.

superjer2000

I don't think it's the AWD system as per my initial post, I also have a 2009 G37x, the only difference there being that the 2009 has more miles the 17" wheels and the non-sport OEM tires. I do notice that the Blizzaks, as soft as they are, actually seem to be a bit more confidence inspiring than the Dunlops which is pretty disappointing. At the rate I drive, I should be able to get rid of the Dunlops in, oh, 4 years. Again, as was suggested earlier though, perhaps they will be a bit better when they are broken in more.

superjer2000

zmzmzm's above comment about alignment was right on the money. In summary, my concern was I had a new 2010 G37x that handled like the front end and back end were from different cars. It always felt like the rear end wanted to swing around to the front even on relatively gradual curves taken at the speed limit. This became more disconcerting as the roads become more icy. The car handled much worse than my previous car (2009 G37x (i.e. the same car - so I knew how this car SHOULD feel)) and even less confidence-inspiring than our Sienna minivan. It always felt like the car was going into oversteer, which felt dangerous on winter-roads.

I took it into the dealership a week or so ago and they looked at it and like I guessed would happen, they couldn't identify a problem. Part of the issue was that when I brought it in, the roads were quite icy so it would be harder to distinguish true slipping from the conditions from the problem I was experiencing. Plus without knowing exactly how the car SHOULD feel, a technician may not feel the same thing. Still, after driving the car more over the last week I knew I couldn't handle the car this way so I called the dealership and told them I wanted an alignment done and I'd be willing to pay to the extent that nothing was uncovered.

After searching online, I told the dealership that I thought the issue might be the rear toe, BUT it appears it was actually the front toe. The two front wheels were +0.12 deg and -0.12 deg. Spec is from 0 to .08 (positive for both). They fixed the front toe to now be +.05 and +.03 and the difference is like night and day. Googling the results led to the conclusion that negative toe (i.e. toe out) on the front can cause oversteer.

NOW the annoying part is that the service adviser ran through the alignment report quickly not bringing up the fact that the front toe was out (by a full .12 degrees) making it sound like they didn't actually notice anything was out when they did the alignment so they proceeded to charge me the $150. I didn't look at the alignment report in detail until I got home and was able to check their specs against the FSM posted here.

I think I am going to call the dealership back - Infiniti's warranty states that in the adjustment period they will correct items like this for 1 yr 20,000km. My car is 1.5 months old and has 1,600km on it.

Anyways, I wanted to report back in case anyone else experiences something like this and uncovers it by a search. I'm not sure how the toe could be so far off from the factory (my belief is that .12 deg, especially on the toe-out side for the front is pretty far off), but I am now actually enjoying the car like I enjoyed my 2009.