I have an 06 Sport with Proteus 18" wheels. Tires are Pirelli P Zero Nero 225/40/18.

Recommended pressure on the door jamb is 40 psi Front/35 psi Rear.

That's where I've got the tires now, but tech spec says tires can take as much as 51 psi.

Anyone had experience/results with different pressure settings?

Thanks...

 

what tech specs???

 

Pirelli's tech specs for the tires say max psi is 51. So they can definitely go higher than the "recommended" 40/35.

 

So what if the TIRE manufacturer says the tires can go to 51 PSI. You should listen to the CAR manufacturer as to the proper tire pressure to inflate them to.

If you use a higher pressure than what the car manufacturer recommends, 1) less of the tire tread will be on the road (aka they will be over-inflated.) 2) you will suffer a harsher ride (due to the higher pressure).

The tire manufacturer has no idea of the weight of the VEHICLE. That's what is the major determining factor in the correct tire pressure to use. They build their specs o that their tires can be used on a wide variety of vehicles (not all of which have the same weight nor load capacity.)

 

What you are reading on the tire is the MAX tire pressure. Meaning that the 51 is the MAX with a full load. not recommended you do that.
X-Type

 

I run mine at 37 PSI on all four..Good ride, good tire wear.

 

Stick with what's on the door jamb and only deviate a few psi depending on your comfort preference and the wear characteristics of the tires.

 

If your going to the drag strip with stock radials, your optimum tire pressure is between 21-25psi in the rears and 35-45psi in the fronts.. You want the front tires high to reduce resistance, and the rears low to help shift the weight to the back tires..

 

My 2003 recommends 30/30. It's hard to believe they will recommend 40/35 - such big difference.

 

My 05 sport w/17s says 38 front 35 rear

 

+1 w/ what some above have suggested. Run what the vehicles door jam label is suggesting unless you're doing a track session. Your vehicles suspension is tuned to specific tire pressures. Running too high of pressure will over-tax your suspension. Think of how much higher a basketball bounces when you continue to add air into it and how poorly it bounces when under inflated.

 

Actually am getting hooked up with some Kumho Ecstas ASX this afternoon. My tread was very low and with winter coming I want good traction. My left rear tire was loosing pressure constantly, so it probably needed a patch. I think the continentals that were on it were original and I have 39K miles.

 

You'll lovethat tire JJ..That's what I have..I run 37 PSI in them, FYI

 

Thanks Dennis, you running that pressure on all 4 tires???

 

Yes..Ride is slightly firm, but tire wear is even..

 

I just installed my winter 16 inch rims and tires. Running 38psi up front, 35 in the back. After 3 seasons of experimenting, seems to be the right combo for my set-up. Seems that different tires like slightly different psi. If you stay somewhere in between the comfort and high speed settings all the way around, you should be good.

I was pleasantly suprised whenI pulled off my summer 17's (Hankook V4) that the treadwear was very even, none of that inside edge wear on the fronts that the X is known for. I chalk it up to having my alignment tech set the toe to as close to zero as possible.

 

I've got to say, after my alignment and the new Kumho tires, my ride is quite a bit better.

 

Hello all, long time lurker 2nd time poster (sorry I forgot to introduce myself the first time). I own a 2002 X-Type Sport 2.5L which I have had for just over 3 year's. I too just got a set of the Kumho ASX's in 225/45/17 for my Aguila's and I must say what a great tire for the price. Definitely wins best bang for your buck award.I previously had the Fierce UHP which were originally Goodyears attempt at a cheaper Z rated tire alternative to the F1 eagles. Kelly has since bought the rights and they are now called the EVO'Z's. Anyway the Z rated ASX's are by far a better tire. Low noise, great traction and just looks good. Big thanks to Dennis and the others for recommending this tire. Love em......

 

I don't have the user manual (X-Type 2005) with me because I'm at work, but if I recall correctly, it says 38 front 35 rear for 16 and 17 inch tires, and 40 front 35 rear for 18 inch tires.

 

Yes Sevren the manual does say 38 front 35 rear for performance and 30 all around for comfort if using the oem conti's. It also says to add an additional 2 psi if using another type of tire other than than the conti's for the comfort setting. So basically 32 psi all around for comfort if using another brand of tire.