Nitrogen in tires

**Corey_R** · 21-06-2011, 11:32 AM

I feel that Mavericks post here which reproduces an RACQ article on the subject is the most valueable post for anyone to read on this subject.

The article touches on the true reasons for using 100% nitrogen which is 1) the (variable) moisture content in "regular air" and 2) nitrogen is less likely to escape through the porus tyre surface than the other components of "regular air".

Chad Knaus and Larry McReynolds recently discussed this on an episode of "NASCAR Performance on SPEED". No offense to anyone here, but I'd take their word on the subject over anyone here (or even the RACQ!). They stated that nitrogen is 100% necessary in higher levels of motor competition due to the fact that it doesn't have the moisture which then heats (from the tyre friction and brakes etc) and expands and creates havoc with the handling of the car. But they then went on to say that in the lower levels of motorsport if Nitrogen is not an option, using an "air dryer pump" to fill the tyres with can approach the same level of usefulness of pure nitrogen, as it helps get rid of the moisture which causes all the handling issues for them.

On a road car, I don't believe the above is a factor. However, I know that trucking companies do use nitrogen because of the heavy loading on their tyres causes sidewall flex, which produces heat, which expands the moisture and causes them issues. Therefore they use nitrogen too.

In my experience, I had some Yokohama 165/55R14's (can't remember the model) filled up with nitrogen several years back. In the 4 years they were on the car, I never had to top them up once. They did lose ~2 psi over the course of that time, however, you could put this down to me attaching the digital guage to the tyres to check the pressures ~once a year over that time (or even the accuracy of the guage). The previous Yokohamas I had on that car had to be topped up at least once ever six months. So I did see an advantage there. Whether that's worth the ~$20 to $40 the tyre places charge for nitrogen... well, that's up to the individual.

I don't have nitrogen in my Golf R...

**bigfoot** · 21-06-2011, 12:26 PM

Originally Posted by Corey_R

They stated that nitrogen is 100% necessary in higher levels of motor competition due to the fact that it doesn't have the moisture which then heats (from the tyre friction and brakes etc) and expands and creates havoc with the handling of the car.

Bingo. You Can leave the pits knowing the pressure will only fluctuate .5 psi rather than 2 to 3 with air

**Treza360** · 21-06-2011, 09:43 PM

All I know is that I filled my tyres with Nitrogen back in 2009 and in three months I lost half a PSI in each tyre (from that thread) and they didn't charge me for the top up. That's as opposed to losing ~2 PSI every 2-3 weeks. Haven't bothered since because it's just easier to check ~ fortnightly when I fill up at the servo. Really there are only two and half negatives for using Nitrogen 1 and a half reasons are that you have to pay (even if it is only $20 dollars or so) and to maintain couple of real world positives you need to keep filling with Nitrogen. The other reason is that you may become lazy/complacent with checking your pressures as if you develop a slow leak you won't notice unless you're checking regularly or have pressure monitors.
Cheers,
Trent

**kaanage** · 21-06-2011, 09:54 PM

Nitrogen is good the person who views a car as an appliance and only fills it with fuel and takes it for servicing (or repairs when it breaks down).

Nitrogen is probably better for racing with hot conditions and heavy vehicles where the pressure rise from moisture would need worrying low pressures and destructively high operating temperatures for the operating pressure to be correct. With light vehicles and cold days, you can use the pressure rise from the normal air fill to help get tyres up to operating temperature.

**Preen59** · 21-06-2011, 09:56 PM

You're exactly right, dude.

Originally Posted by kaanage

With light vehicles and cold days, you can use the pressure rise from the normal air fill to help get tyres up to operating temperature.

Trying to make that point was what got me banned. Hahaha.

**Banzai** · 21-06-2011, 11:04 PM

I'm more than happy using Nitrogen.
It is rarely 100% but the low moisture content and larger molecules are great for tyre stability.

You will find that many of the modern race teams are now using dry air. Similar stability to Nitrogen so tyre temps are more consistent and they don't care about long service life.

**Blitzen** · 21-06-2011, 11:12 PM

I don't understand why you would pay to have Nitrogen put in your tyres, then pay to top them up again too, when you can top them up for free at any servo... It's not like you will be landing the car on an aircraft carrier...This is yet another thread that has been covered to death before... 'SEARCH FUNCTION'...

**Treza360** · 22-06-2011, 12:31 PM

I wasn't charged to top it up.

A lot of people don't understand why we spend the money on cars the way we do when all they do is get us from A to B and depreciate. At the end of the day us car enthusiasts are a special breed of people. At the end of the day it's not detrimental to the car or anyone else so aside from the discussion on the pros and cons, I don't understand why some people get so worked up and personal about it.

Cheers,
Trent

**Corey_R** · 22-06-2011, 01:32 PM

+1 for Trent.

Some people spend a few hundred changing their aircon controls from blue to white. Others spend thousands on new wheels. Some spend a few hundred on nice number plate brackets/covers. Some spend hundreds to tens of thousands soley on performance parts... some get both.

Each to their own