Anyone else with a G37x Sport think the ride quality is crap? My wife can't stand the ride quality. Bumpy and shudders on smooth roads. We test drove the car initially, but after living with it for a week now, the ride seems bad. Current mileage is 275. Anyone think it may soften up a bit over time? The x sport does not have the sport tuned suspension. I am thinking of changing the tires to the Michelin Primacy MXV4 225/60R18 to improve ride quality. Overall tire diameter will increase by 1.7" therfore I need .85" clearance for additional radius increase. Anyone see any problem with this other than speedometer with be read 6% lower? The stock dunlop sport maxx A1 225/50R18 seem way to stiff. I have a 2007 G35 Sport and that sport tuned suspension rides better than the G37x with my 19" rims. I have driven an 09 g37x with the 225/55R17 tires and the ride is better. The dealer offered to swap the tires and rims for the G37x 17" setup, but I rather keep the sport 18" for when I go to sell it. I believe the 17" tires are a Goodyear RSA which do not get the best reviews for ride quality. Looks like I will be selling the stock tires on Ebay.

 

Hmm....after owning an 06 G35 6MT for 3 years and and a G37xS for a few weeks, here are my impressions related to your ride quality post above:

I feel the G37xS ride is quite luxurious in comparison. Much more compliant than my previous G35 with sport package. Perhaps Infiniti has changed much of the suspension since my 06 G but the more compliant nature of the G37xS for the daily driving on crappy Boston roads this time of year is a nice change. Much more isolated (good thing) at 2/10th. My sense for daily driving is that it has less to do with tires and more to do with the sport vs non-sport suspension. But, had my first opportunity to go full-bore into one of my favorite off ramps today (9/10th) and found the G37xS to be rather squirrely, particularly the rear end. Perhaps I was just carrying more speed than I would have in the 06 G but still rather disconcerting. I do understand that the G37xS doesn't have the sport suspension. My initial sense is that the all season 50 series tires are the culprit at 9/10ths. Perhaps softer rear shocks of the non-sport. Will report more over time. The net = the G37xS is unquestionably a more compliant ride. Sorry for the digression...

So, to your point robswid, 17" wheels with a higher profile tire could certainly help but my guess is that you probably won't be able to dial out all the "bump and shudders" with new tires/wheels assuming that I am understanding your dilemma correctly. Although I indicate above (in my blatant thread hijack) that my G37xS is softer than my G35 6MT, there is no question, as you know, that these cars are suspended as true sports sedans in any iteration. I wouldn't expect a big change in ride quality with new tires in relaxed, day to day driving. Could be wrong...

Personally, I would avoid exceeding the rolling diameter of the stock 225/50/18. Too many electronics involved, particularly in the x.

 

I assume that your wife had 225/50/18 now. not recommend to change to 225/60/18 the car will sitting higher than normal.The 17" stock will ride very smoother and quieter than your 18" now.I have 2 set of wheel that how i know.Get another set from our G forum.Don't go to the dealer.They will cost you ploblably 1400-2000.

 

If you like the car but want the softer ride, Definitely go with the 17" wheel package.
Do not go to a larger outside diameter tire.

 

If you think a G37xS rides hard, from what I gather the RWD S has an even stiffer suspension. Good for me cause that's just how I personally like how it feels once I'm on the hwy BUT I can understand what you mean, it's not for everyone.

 

Assuming it's cold where you live, the tires are stiffer when they're cold, so the rubber isn't as forgiving. Did you buy your '07 new? What time of year? The suspension will soften up a little after about 2K miles.

AWD is heavier than RWD.

Also check your psi, should be 32-34 range.

 

I have an 07 G35Xs to me it does not ride hard, it is firm, but not hard.

The G35 S has two different size tires, the rears are 245 45 18, the fronts are 225 50 18.

In my opinion the G35Xs tires (225 50 18) are not wide enough for true stability and should be 245 45 18s. I talked to Tire Rack and they recommended that configuration as the largest size the stock wheels would handle.

The smaller tire size is why some of us complain when going around a nice corner at speed, the car begins to feel unstable as if it would let go.

That said, I concur that changing permenantly to 17's is a huge mistake. Using them for winter is a totally different story.

You have a lot of good advice here. Good luck with your choices.

 

The smaller tire size is why some of us complain when going around a nice corner at speed, the car begins to feel unstable as if it would let go.

Had 235/45s on 7.5" x 18" wheels on my `06G35. That was a better setup for performance. So, agreed, too much sidewall flex on my G37xS with 225/50s for spirited driving.

Personally, I think a 7.5" wheel is too narrow on any S model. The xS should have 235/40s on 18 x 8.5 on all four corners, at least as an option. Perhaps a similar setup with 19" wheels as well.

 

for a soft and squishy ride...go cadillac or lexus

 

The ride quality seems to be getting better. The bobble head effect, as my wife calls it, seems to have gotten better. It has been brutely cold below zero in chicago and an wondering if the extreme cold has something to do with it. Tire pressure was the first item I checked. I adjusted to 33psi per the manual. The wife seems happy, so I am happy. I still think the suspension seems stiffer than my 07 g35 RWD sport sedan with 19".

 

Along with your opinion of the ride stiffness, how comfortable are the Sport Seats?

I'm in the decision process now.

thanks

 

Along with your opinion of the ride stiffness, how comfortable are the Sport Seats?

IMHO, the sport seats are 1000% better than the standard seats. Adjustable bolsters and deeper bolstering make the difference. The new seats clamp you in place perfectly. Or not - your choice. I floated around the standard seats in the `06 G35 badly. One note, I am 5`9" and medium build. If you are big, broad, fat, whatever, you might not like the sport seats.

 

Softer ride = Buick... Invest in one

 

+1

I even find the G35S suspension to be soft...
...but that's compared to my old avatar-nissan-350z.gif?t=1192306014

 

Theres your problem...The cold makes your tires turn to rock. Once the weather starts warming up, you will feel a massive difference. For example, put a rubber band inside your freezer and leave it in there for 1 hour and then take it out. It wont be nearly as rubbery