Nitrogen in tires is pretty much pointless. First, air is 78% nitrogen anyway. And "pure" nitrogen is only 95% pure. Having pure nitrogen in your tires may help retain pressure a little bit, but not substantially. And if you ever need to inflate your tires, you're limited to doing it with nitrogen or you've just undone the effect of having nitrogen in there in the first place. If the dealer did it on your new car gratis, great. If they want you to pay a premium to have them inflated in that way in the future, skip it.

As for the pressure, as you can see from the comments people have varying opinions about how much above or below the recommended cold temp setting. One thing that is NOT good though is having your tires at different pressures. 1 or 2 psi probably isn't going to make a difference, but generally speaking you want to try to keep them all at the same pressure.

Personally I'm running 36 on all four tires, but that's just because the temperature has been fluctuating so much recently that I don't want to set them to 33 and then find them at 30 on a cold day. I'd rather have them a little high than a little low.

 

I use a proprietary blend of 78% nitrogen.

when cold, I use the number on the plate at the drivers door. helps me from figuring out what to do.

 

I had also heard reports that running just 78% nitrogen was the optimum amount for the best performance.

After spending some time searching, I found a machine at Costco that claims to take in regular air, and converts it to the ideal 78% nitrogen and 21% oxygen (and another 1% of miscellaneous gases which are insignificant).

I have been using this machine to inflate my tires for several years now, with great success, and I would never go back to using regular air from a service station pump.

I am always cautious to use this machine in a well ventilated area so that I am not overcome by the gases that it produces.

 

I also try to find a happy medium on air pressure. The recommended on the door says, I leave it at 35. Georgia doesn't get too cold, but any cooler/less cooler days seems to compensate OK around there. In the summer, I usually leave them at the recommended, since it's always hot and humid here!


Do you mean at their tire center or ddi you actually purchase a tire inflator at Costco that does this?

 

You should have done more searching. My machine from PEP BOYS does all your Costco machine does and even filters and captures the Argon so I can use it in my incandescent bulbs. Great idea on the ventilated area. I knew a guy whose cousin's brother-in-law by marriage said he heard a guy almost died using the Costco air machine inside a packing box.

 

I use this guy. My tires have a touch of halitosis.

 

Just got this gauge on sale at Amazon. $28 marked down from $90. Incredible deal and excellent product.


Hurry. The price won't hold more than a day or two.

 

nitrogen tire fill is a scam, everyone knows it

 

lol. Lots of the same or similar for 20 -30 bucks.

 

Where?
That is <$30.

 

Just look at the bottom - 'sponsored items' on the Amazon page

 

Yeah many similar but not the same. Some are digital, some are gauges, etc. The one I linked to actually is not the one I bought. Same thing but I paid less. Some of them appear and disappear from Amazon and prices change regularly. Sometimes they're sold by 3rd party vendors.

Bottom line, that one is very good, IMO. I went through 3 of those red handheld ones in about 5 years. They're crap. I even tried changing the batteries in one and it just fell apart. This one just takes 2 AAAs.

 

I got a manual metal gauge about 20 years ago, non of that digital crap, still works and accurate

 

I use an old metal analog gauge as well - got it in 1998 when my girlfriend (wife since) and I bought a used car. Anyway, I have mine RDX adv set to 35psi cold. Cold, in my case, is my garage after sitting overnight.

I check it every month and it lives in a charmed life in an attached garage so I'm not as worried about temperature fluctuations. The only thing I noticed is that the TPMS reads a couple of psi high. I have checked it with another gauge and it's definitely high.

Has anyone else noticed it?

 

yeah, its not that accurate. I think they mention that in the manual and suggest you test it every gas fill up or something. It really is to warn of impending doom when the tire loses too much pressure and you haven't figured it out yet.. ;o

 

I figured the would have it read low rather than high to ward of the impending doom earlier.

 

I just want it to be consistent.

 

Hey everyone... I don't mean to threadjack here but since we're talking about pressures and TPMS... Does the TPMS in the 2020 RDX need resetting after a pressure fill or adjustment? I haven't found anything in the manual or in the car systems to suggest it needs to recalibrate or reset after adjusting my pressures. Having had countless Audis, BMWs, Porsches, and Infinitis, I've become accustomed to resetting or recalibrating TPMS after a tire pressure adjustment and this car doesn't seem to have that option. Thoughts?

Thanks!

 

RDX manual says bring into dealer if you find the Tpms and measured psi appears very different. No way to 'set'.

 

No resetting or recalibrating required, ever.

3rd-gen RDX has a direct-read TPMS system with "smart sensors" that directly read the internal air pressure in the tire. The sensors pair with the vehicle automatically without intervention ( assuming compatible sensors are installed in the wheels ), and if new sensors ( different wheels ) are installed the pressure will register within a few miles of driving. Same deal if the tires/wheels are rotated to different positions on the car.

"Indirect TPMS" systems need to be calibrated because they have no physical sensors to read internal air pressure, and instead monitor effective rolling circumference of the tires. More air pressure = rounder tire = bigger circumference. That system must be calibrated after filling the tires to a known air pressure, and it will then alert the driver to changes beyond some threshold. Some recent Hondas use the indirect system, including CR-V.

 

The stuff I learn on this site.
Thanks!

 

The tire pressure that you run depends on MANY variables, tire size, section width, amount of weight on the front tires vs rear tires, and the construction of the tire itself.
There are tires that are rated for 3o something max psi, 44 max psi, now 50 psi max inflation. Each will behave differently. The only TRUE way to know is fill to a logical psi, then after 6 months check VERY CAREFULLY with a depth gauge, and make your adjustments. I run 50 psi max tires , for me about 41 psi works pretty good.
And when my daughter heads back to college next week with a FULLY LOADED RDX the tires will be pumped up 45/46 psi in the rears. I text her a week later to deflate to normal psi after she has unloaded.

 

EDIT TO ABOVE:
I misremembered my past PSI's on the RDX, I ran the tires at 38 front and 36 rear. But after measuring the tread depth today, I will be increasing the pressures by 2 psi each, all 4 tires were running a little light, with most of the tread wear on the edges (underinflated) One of the factors effecting tire pressure is TREAD WIDTH , and I am running slightly wider than stock tires.