Have a new g35x... less than 500 miles
the ride is harsh and thats an understatement
on the advice of some on this board i checked my tire pressure today
found that three were at 37.5 psi and one was at 36 psi
if i lower the pressure to around 32 psi will it dramatically improve the smoothness of the car?
i know that the tire sticker on the door says that it should be 30 psi.
should i lower it all the way to 30 psi instead of 32 psi
i dont want the mpg to go to sh*t
cuz i'm only getting 16 mpg on the 37.5 psi tires

 

Lowering your tire pressure to what Infiniti recommends will definately help to provide a more cushion like ride. I've tried that on my sedan before and there was a noticeable ride difference compared to having it at 37 psi. Yes, you can expect to lose a little bit in terms of fuel economy, though I can't say exactly how much. Still it may be worth trying if you are not happy with the stiffness of your ride.

 

Not sure, but I thought the SedanX's tire pressure recommendation is 33????
I know my '03 Sedan was supposed to be 30 psi. I ran it at 32-33.

Yes, 36 - 37 would yield a harsher ride and substandard performance. Lower it to whatever the sticker in the door says and see how you like it.
My friend runs his at 33 - 34 and it feels great and comfortable. Not harsh at all.

C.

 

running at 36-37 will increase ride stiffness/harshness, but it will not result in substandard performance. It will increase your performance by decreaseing rolling resistance, and it will increase your cornering ability by decreaseing the amount your tires roll under in hard turns. Now, if you increase your pressure to say 45-50, then that might decrease your performance as they will by too hard and will slide too much, along with wearing the middle of the tires. I would say 35 would be a good spot - that is where my 05 X is for daily driving.

 

the stock RS-A's on the 05 X's now are not the greatest tires, but are used on MANY OE applications. They are not really good at any one thing, but acceptible on all things. There are much better tires out their for all-seasons that will ride better for you when it is time to replace.

 

Well said and 100 percent accurate. The key point is reducing tire deformation under heavy cornering loads, which is exactly what running a little extra pressure does. Lowering the tire pressure to 30 pounds will reduce ride harshness a bit though.

The G35 is a performance sedan, and I bought it knowing the thing wouldn't ride like a Buick. Overall I'd say my 6MT sedan with the sport suspension and 18" wheels and tires rides quite well, all things considered.

 

Ride is definitely better on 30psi (recommended for sedan). Mine are 35 psi right now for the additional performance but I think the sweet spot is somewhere between 30 & 35 as I find the ride for everyday driving a little jolting at times.

 

For me, the best upgrade I could make immediately after buying the G35X was to ditch the RS-A's in favor of Michelin Pilot Sport A/S's. I got a decent return on the RS-A's selling them as almost new on EBay and I've enjoyed improved ride and handling from the Michelin's. For those that might say the Michelin's wear too quickly, I've had a lot of success and after 15k miles on these tires, my wear indicates I've got at least another 10K miles to go. Not bad for a high performance tire. I run them at 30 psi and they're wearing evenly.

 

My goodness, it's just a tire. Try different pressures - you're not going to break anything.

 

My stock tires on my 05 X were 17" Bridgestone Turanzas EL42, as far as the ride goes it was great, but I ran them at the reccomended pressure of 30 PSI. I now have the 18" Goodyear NCT5 tires on the sedan sport rims, and I am running them at 34 PSI (1 pound over the reccomended pressure) and they ride about the same, but the handling has improved immensely .

 

I like to stay in between. My tires are always 35 PSI to have better fuel economy and to keep the ride comfortable.

Personally, I think that is a very good balance of performance and comfort.

 

My door also stated 30PSI. Right now I have it at 35PSI. From the dealers lot it was around 40 and it was too stiff, and I did experience some wheel hop. I might lower it to around 32PSI soon.