Nitrogen and air pressures

[schu300]

So I finally ordered and received my new tires for my 06 M45 Sport. We got the new Michelin Pilot Sport A/S tires. When we took the tires to the Infiniti dealership to be installed, the service advisor asked me if I wanted Nitrogen filled instead of Oxygen filled. He explained to me that Nitrogen doesnt fluctuate with the tempreture change outside. I said sure lets try it.

So here is my question to all of you is:

A) Have any of you used Nitrogen instead of Oxygen?B) Do you notice any differences good or bad?C) What tire pressures do you leave your tires at? The sticker on my driver door says 33PSI and the dealership filled them to 36PSI.

Thanks in advance!

[striz923]

pretty decent discussion about this topic here:

zer...tires

I think that 35 is the "recommended" pressure.

[M45Caliber]

check out the nitrogen content of the air you breathe -- then decide (hint - it's about 80% nitrogen, 20 % oxygen).

As an FYI, The manager at Discount Tire said unless you are racing (e.g. F-1, LeMans, etc.) it's a total waste of your money. Spend it on bottled water -- at least you'll get something tangible to enjoy for a high price.

[szh]

I think that 35 is the "recommended" pressure.

Yes!

About 35 to 36 psi is the right place ... to account for the 1 to 2 psi drop that is typical in a week or two. Gives you that small extra margin till you measure and bring back to normal pressure.

Too low a pressure and you are likely to have a safety issue with sidewall flexing way too much (overheating as a result), low mileage, poor handling and excessive wear on the inner and outer edges of the tread.

Too high a pressure and you will have a harsh ride, skittish handling, poor wet weather water evacuation at speed, and excessive wear on the center section of the tread.

Way too high a pressure (above the max listed on the side of the tire) and you might have a blowout at the worst possible moment.

Some other things to keep in mind:

1. All tire pressures should measured cold. In the garage. In the morning. Before you have driven a single mile. Before even the sun has had a chance to warm the tire by heating the black rubber.

2. If you are going to be driving at high speeds (i.e., long trip at 70+ mph speeds), do increase the tire pressure up by 3 to 4 psi over your normal (like around 38 to 40psi). European rules require 7 psi over normal if you are going to drive on the Autobahn at over 100 mph for long distances. This higher pressure provides less flex for the sidewall, and less heat generation as a result.

Z

[MagicM]

I think Nitrogen tires are scam from the dealership, i'am amazed that most people don't know that air is 80% "N", and go up and think "OMFG Nitrogen air they must be special. At 40 Dollars for air stealership can keep their "special air"

[marlin29311]

If you are paying for the nitrogen, it's not really worth it. It's more of a "lazy" mod and people use it so that they don't have to check their tire pressure's as often. If you get it for free, then by all means use - it's not going to hurt or anything. But yes, 78% of the atmosphere is already nitrogen.

As a rule of thumb, it is a good idea to put the tires as 10psi below what the max tire pressure is - aka if your new tires are 45psi, then you use 35 psi. You just want to make sure you don't overinflate your car as to cause buldging, which would cause uneven tire wear.

So if you get the nitrogen for free, go for it. It's not that big of a deal though.

[szh]

As a rule of thumb, it is a good idea to put the tires as 10psi below what the max tire pressure is - aka if your new tires are 45psi, then you use 35 psi.

Ummm ... no, this rule of thumb is not right. Remember that most tires nowadays are 51 psi max pressure, and setting the tire at 41psi would be too harsh a ride in general, for most people.

The correct way to do it is to set it at the pressure that is used for measuring load index - this is 36 psi (set in the era of 45psi max tires and has not yet been changed even though we now have 51psi max tires). Then, adjust up or down (not too far down) to get the most reasonable tire wear over time, by measuring the tread depth using a depth gauge, at various points along the tread.

I heartily recommend getting a good pressure gauge (my personal favorite is a bit expensive though) and a tread depth gauge (these are totally inexpensive at any parts store).

So if you get the nitrogen for free, go for it. It's not that big of a deal though.

Agreed on both points.

Z

[BigB4]

Hi all,

My name is Broadus and I'm a member of the Michelin Tire Tech Team. I thought you might like to know Michelin’s position on nitrogen, as well as my own personal experience. Several chemical companies are promoting the use of nitrogen as an inflation gas to the tire industry with claims of improved tire performance. The air we breathe and use to inflate tires chemically consists of 78% nitrogen, 20% oxygen and 2% other. When using nitrogen as an inflation gas, the composition of nitrogen increases from 78% to near 100%. Michelin supports the use of nitrogen based on its ability to better retain air over a period of time.

I have personally noticed a difference with the ride of my vehicle. It seems to handle much better and the ride is smoother. So, I would agree with the others that if it is included by the tire dealer, use it. As to whether it’s worth a premium, that’s a personal value judgment (we get it free here at work). The most important factors in tire life and performance are frequent air pressure checks and regular tire rotation and balancing—and of course selecting the right tires for your vehicle.

Regarding your question about air pressure, as you probably assume, Michelin's recommendation is to use the inflation pressure specified by the vehicle manufacturer which can be found in the owner’s manual or on the sticker on the inside of the driver’s door.

Hey schu300, did you get the new Michelin Pilot Sport A/S Plus tires? How do you like them? They just came out so we’re eager to hear feedback.

Best,

BroadusMichelin Tire Tech Teambroadus.tiretechteam (at) us.michelin.com
Modified by BigB4 at 1:55 PM 11/17/2008

[WDRacing]

When I was active duty USAF, we used Nitrogen instead of O2 because of the possible water content from a standard air compressor.

[szh]

My name is Broadus and I'm a member of the Michelin Tire Tech Team. I thought you might like to know Michelin’s position on nitrogen, as well as my own personal experience. Several chemical companies are promoting the use of nitrogen as an inflation gas to the tire industry with claims of improved tire performance. The air we breathe and use to inflate tires chemically consists of 78% nitrogen, 20% oxygen and 2% other. When using nitrogen as an inflation gas, the composition of nitrogen increases from 78% to near 100%. Michelin supports the use of nitrogen based on its ability to better retain air over a period of time.

I have personally noticed a difference with the ride of my vehicle. It seems to handle much better and the ride is smoother. So, I would agree with the others that if it is included by the tire dealer, use it. As to whether it’s worth a premium, that’s a personal value judgment (we get it free here at work). The most important factors in tire life and performance are frequent air pressure checks and regular tire rotation and balancing—and of course selecting the right tires for your vehicle.

Regarding your question about air pressure, as you probably assume, Michelin's recommendation is to use the inflation pressure specified by the vehicle manufacturer which can be found in the owner’s manual or on the sticker on the inside of the driver’s door.

Hey schu300, did you get the new Michelin Pilot Sport A/S Plus tires? How do you like them? They just came out so we’re eager to hear feedback.

Best,

BroadusMichelin Tire Tech Teambroadus.tiretechteam (at) us.michelin.com

Welcome to NICO, Broadus.

I am sure that a lot of us will have lots of questions for you! When did the Pilot Sport A/S Plus get released, by the way?

My first question: I bought Pilot Sport A/S tires (in a 245/45-18 size) in spring of this year, but have to admit that I am a bit surprised how fast they are wearing.

Given their 400 rating, I was expecting to get near 25k to 30k miles out of them, but I am currently at 8k miles of use, and they are down to 4/32" and 5/32". I suspect that I will have to change tires at the 13k to 15k point. Is this faster than you would expect to see on these tires?

Z

[maxnix]

Sure wearing a lot faster than my PS2 did (22K). Could have gotten more if wife would yield car to have tires flipped.

[szh]

Sure wearing a lot faster than my PS2 did (22K).

I know! I am quite surprised by this too ...

Z

[BigB4]

Hi Folks,

Thanks for the welcome. Szhosain, the Pilot Sport A/S Plus was introduced in September of this year. More sizes are coming in March 2009 but it looks like the most popular standard fitments for the M45 are available now.

Our own internal testing shows the Plus improves dry handling, wet braking, wet handing and most dramatically, wear (hence the addition of the 45,000 mileage warranty) over the previous generation tire. Tire Rack just released their test on it here: http://www.tirerack.com/tires/...d=115

Regarding your own wear issues, I can see your concern. We would recommend having your tires inspected by a participating Michelin tire retailer. Once the retailer inspects your tires, please have them call Michelin Consumer Care while you are at the dealer to discuss the findings at 1-800-847-3435. Ask for a senior tire representative and myself or another rep will discuss the situation with you.

As you know, treadwear or life expectancy is influenced by many factors, such as type of vehicle, driving habits and style of driving (around town driving results in quicker wear rate than highway driving), geographical location (tires wear quicker in a mountainous region), how vehicle is maintained (regular alignment/suspension checks), how tires are maintained (proper air pressure and rotations). In general, ultra-high performance tires are not known for long wear life due to the soft compound that lets them hold the road. Personally, PS2s are my favorite tires but it is not what I choose for daily driving on my Acura RL (although it would be fun).

But, contact us at the 800 number and maybe we can learn more about the situation.

Thanks,

BroadusMichelin Tire Tech Teambroadus.tiretechteam (at) us.michelin.com

[szh]

Thanks, I will do so!

Z