Recommended Tire Pressure Help Please - Yoko 255/50/20 Spec X

[Clarky]

Hi, Just purchased a 2010 Murano. The stock Toyo tires are kaput and I am having Yokohama Parada Spec X in size 255/50/20 put on this weekend. I was hoping to get some feedback from people running this particular tire and their thoughts and experience with tire pressure. I would like to know if anyone has played with the pressure up or down and what their experience (positive or negatitve) with the adjustments were. Also in general, what are the implications on ride quality for a higher or lower tire pressure.

Thanks in advance.

[Pilgrim]

Do some searches and you will find this debated at GREAT length. Your question has been asked and answered many times.

My answer: check the maximum rated pressure on the sidewalls; if more than 40 PSI, I recommend running 40 PSI all around. It's completely safe, improves handling, and may help fuel mileage slightly.

My explanation of this position is in a number of threads which you will find by searching.

[red kiosk]

I have been running 37 PSI on mine since they were installed. 2009 LE with the same tires. No problems at all. Nice road feel, but not too harsh. I do have separate snows for the winter though. Hope this helps and take care!

Jim

[MuranoSV]

I run 35~36 psi on mine and feel good.

[MuranoDriver]

Isn't tire pressure basicly the same for all passenger vehicle tires?

I've ran 38-40 in most vehicles and they all had very different tire sizes.

[Halwg]

Have you considered having your tires filled with Nitrogen?

There are several compelling reasons to use pure nitrogen in tires.

First is that nitrogen is less likely to migrate through tire rubber than is oxygen, which means that your tire pressures will remain more stable over the long term. Racers figured out pretty quickly that tires filled with nitrogen rather than air also exhibit less pressure change with temperature swings. That means more consistent inflation pressures during a race as the tires heat up. And when you're tweaking a race car's handling with half-psi changes, that's important.

Passenger cars can also benefit from the more stable pressures. But there's more: Humidity (water) is a Bad Thing to have inside a tire. Water, present as a vapor or even as a liquid in a tire, causes more of a pressure change with temperature swings than dry air does. It also promotes corrosion of the steel or aluminum rim.

Read more: Nitrogen vs Air In Tires - Why Nitrogen in Tires - Popular Mechanics

[red kiosk]

If I remember correctly, didn't njjoe have a good source for 78% nitrogen that he was recommending? Maybe not suitable for race tires, but good enough for consumer tires. Take care!

[Pilgrim]

Originally Posted by MuranoDriver

Isn't tire pressure basicly the same for all passenger vehicle tires?

I've ran 38-40 in most vehicles and they all had very different tire sizes.

No not really. Some have "maximum rated" pressures of 40 PSI, some 44 PSI, and although I haven't seen any lately, it used to be fairly common to see maximum pressures of 36 PSI. The maximum rating is always printed on the sidewall.

The speed rating and the profile will have an influence on tire pressure. Lower profile tires usually have higher pressure ratings, and I believe that's because it's important that their sidewalls not deflect enough to cause rim damage when hitting a pothole or irregularity in the road; they also are higher to stiffen the sidewall for better handling. Here are the current speed ratings:

Rated miles per hour (km/h)
M: 81 (130)
N: 87 (140)
P: 93 (150)
Q: 99 (160)
R: 106 (170)
S: 112 (180)
T: 118 (190)
U: 124 (200)
H: 130 (210)
V: 149 (240)
W: 168 (270)
Y: 186 (300)

Most of us don't see all of these ratings. I have encountered H and V most often. Generally speaking, the higher the speed rating, the higher the maximum air pressure will be. I haven't yet encountered passenger tire max pressure ratings higher than 44, but that may just be the tires I'm using. Truck tires often have higher pressure ratings, and a wide range of permissable pressures to suit various work applications.

If anyone wants to learn more about tire sizing and ratings, I recommend: Tire Tech Information - How to Read Speed Rating, Load Index & Service Descriptions

[Halwg]

Originally Posted by red kiosk

If I remember correctly, didn't njjoe have a good source for 78% nitrogen that he was recommending? Maybe not suitable for race tires, but good enough for consumer tires. Take care!

Yeah, just breathe!

[MuranoDriver]

You definitely shouldn't go over the maximum rated. I don't think I've ever had any tires with less than 44 max and they've ranged from 35 series to 70 series and everything in between.

Only been buying tires for 11-12 years though.

[hokey777]

The recommended tire pressure for your vehicle is located on the drivers door jamb. I run mine at 36.

[zebelkhan]

You can experiment with different tire pressures but you need to keep two things in mind:

1- do not exceed max tire pressure
2- Maintain factory pressure variance between front and rear

On my MO I kept tires 4psi above recommended. On my Prius, I keep them at 42 and 40.