vartig

Hey RX drivers,
Hope you all had enjoyed your weekend with your RX
I was wondering if your RX's tires are filled with Nitrogen too.
Well I got my RX 350 filled with Nitrogen from my dealer and I was thinking about checking the air pressure but I have no idea where to go? and how often should I check it.
any ideas?

Thankss

SteveCraig

Don't be too worried about it. Get an old-school mechanical gauge to check the pressure. You can get a relatively good for home use garage air compressor for less than $50.00. This is the style that plugs into the lighter socket in any car.
Alternatively, go to any place with a compressor, tire shop, repair shop, some gas bars have them coin-operated.
The air we breathe already has 78% nitrogen.

fastnoypi

Yes, don't be worried about it. While SteveCraig's advice is good, the lighter-plug-in style compressors are not very durable and tend to burn out with regular use.

Get yourself a small 1-3 gallon air compressor that plugs into a wall. They range from $50-70. Harbor freight has one for 50 and they more versatile with other accessories. I've used my little 2 gallon compressor for years around our cars to inflate tires, blow dust from interior crevices, dry off wet wheels and water beads, etc..

If you are a member of a BJ's or Costco wholesale club, they offer a free tire check/fill service.

Nitrogen has a lot of good qualities for tires in race cars but you will not experience any benefits in a commuter car.

Check your tires cold. I check them once a month or sooner if i think they visibly look low.
You can get a cheap stick style mechanical gauge or spend a little more on a dial gauge type with an extended hose.
I highly recommend an Accu Gage dial gauge. They are American made and their warranty is excellent at $3 for any repair. I've had mine since '91 and warrantied it twice from accidental dropage that threw off the calibration.

RX330inFL

What is perhaps as important as the use of N2 gas is the quality of the product. As this is processed, it is usually low in moisture. Though, any quality shop who maintains the moisture trap on the shop's compressor will suffice. Over the years I have been more worried about the quality of the air used than what the air was composed of.

dwlink

I keep one of these in each of our cars. Very reliable, well-built, and incredibly accurate and easy to read.


As for nitrogen filled tires, you can either be the one of the fools that pay for 99% nitrogen in their tires or get 78% nitrogen in your tires for free. Unless you have a race car, a private jet, or a space shuttle, you do NOT need pure nitrogen in your tires.

The two good things about having nitrogen in your tires is:

1. N2 molecules are larger in volume than O2 molecules so if you have a poor habit of topping up the air pressure in your tires then N2 is the way to go as your tires will bleed pressure slightly slower over time

2. The bigger benefit is that you wont have water vapor in your tires. N2 alone has a higher gas constant than air so for a given density, its pressure sensitivity to temperature is slightly higher than air if you treat it as an ideal gas. However, when you throw water vapor into the mix and consider the boiling point of water, then the mixture of junk inside your tires as a whole exhibits a non-linear pressure gradient as any water vapor heats up inside your tires on a hot day. In this case its better to have a "dry" tire filled with N2.

Here's another marginal benefit if you have a sunday driver that you only take out once in a while:

If you live in a substantially humid climate and fill your tires with air the water vapor will condense over time and if your car sits in a spot for a while that pool of water on the inside of the tire may affect the inside lining and degrade the life of the tire.

fastnoypi

if you didn't get your tires mounted by a dedicated race team with a high budget, chances are you already have water vapor in your tires.
Its a moot thing to worry about since your local tire installer 98% of the time uses a water/ dish soap mixture to lubricate your tires to get them mounted.

RX330inFL

Sorry, you lose this round. While the O2 molecule is heavier it is also smaller. Wrong premise. Back to chemistry class for you.

raylor4

The 2011 RX owner's manual recommends checking the tire inflation pressure every two weeks, or at least every month. A standard tire pressure gage can be used with nitrogen. If you want someone to do it for you, any tire shop will do it. I like American Tire. BTW, I think it's OK to add air to nitrogen in an auto tire to adjust pressure. Air is mostly nitrogen anyway. I think this nitrogen into tires thing is overkill. I can understand nitrogen in an aircraft tire because of the extreme temps they endure.
I think correct tire pressure is a good investment in time, but fussing about nitrogen isn't.
Ray A.

LeoDLion

I won't fill my tire in LA.

dctex99

Most importantly check your air after you have driven in the rain for a couple of days; your tires do soften and
some air escapes; most of us are using 34 lbs tho Lexus says 32 on many tires and wheels. I recently saw a Toyota Prius on a New Toyota lot and the "ADD ON" sheet said $99 for Nitrogen in the tires, and the ugly green caps!! What a joke...

Woodrow

I happen to work about a mile from our Lexus dealer, so it's easy to swing by, have them check the pressure in all the tires (including the spare), and say hi to my Service Advisor. When it's just as easy (and free) to use nitrogen, why not? We can easily argue that there is minimal upside, but I can't see ANY downside.

Also, O2 expands and contracts more when tire temps change. Between not needing to adjust for air/tire temps and not losing air pressure as fast due to the larger molecules, nitrogen reduces how often you NEED to check the pressure. Better pressure stability may impact tire life, but honestly, unless it's really easy to maintain 99% nitrogen, I tend to agree that we won't actually see an advantage that outweighs the effort.

corradoMR2

My stance on nitrogen-filled tires as well.

dwlink

1. N2 molecules are larger in volume than O2 molecules so if you have a poor habit of topping up the air pressure in your tires then N2 is the way to go as your tires will bleed pressure slightly slower over time

Logic fail.

And to further my original statement: http://www.getnitrogen.org/pdf/graham.pdf

Quiz: From the paper above, describe the differences in the electron configuration of O2 and N2 molecules. Why does this result in N2 having a larger average molecular diameter?

jfelbab

This is a fallacy. Both Nitrogen and air, which is 78% Nitrogen BTW, react identically to temperature changes. It a physics gas law thing. (http://en.wikipedia.org/wiki/Gas_laws)

Way too many people still believe this myth.

Good read:
http://www.tirerack.com/tires/tirete...jsp?techid=191

fastnoypi

link redirects you only to Tirerack's main site.