Tire is low .. where to fill in sj ? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

nefarious986 · 09-11-2008, 04:39 PM

Does any Bay Area (CA) member know where I can go to get my tire refilled with nitrogen besides the dealership ?

I think right now its nitrogen filled directly from the dealership, but the tire is 1/2 flat.

Is it ok to mix Nitrogen and O2 and just refill (temporarily) at a gas station pump ?

Topless · 09-11-2008, 04:59 PM

Maybe stop by your local tire shop and check for a nail in the tire. It got low for a reason. Many tire shops will refill with nitrogen on request but any old compressor will give you a nice clean 80% nitrogen blend.

Jaxonalden · 09-11-2008, 06:57 PM

Why are you worried about refilling with nitrogen? All nitrogen is is a dry non flammable gas. In aircraft applications it's recommended to fill the tires with nitrogen (as opposed to dry air) because of the extreme temperature swings the tires go through (-60 thru 150 degrees in a matter of minutes). It provides a more stable, constant pressure.

Down here on the ground, there's nothing wrong with using compressed air. Preferably air from a compressor with a dehydrator. If not, so what, tire pressure and tire condition should be checked on a regular basis.

BTW, to truly fill a tire with nitrogen you first need to purge out all the air before filling the tire. Good luck going through that process.

Paying a dealership to air up your tires? Please

nefarious986 · 09-11-2008, 07:49 PM

Thats exactly why I thought Porsche put Nitrogen in the cars stock ? It maintains pressure under heated use much better than regular oxygen. Less checking & maintenance plus some minor stuff with better mileage since your tires are always 'perfectly' inflated.

I could fill it with air, but considering I got this car 8 months ago (directly from Porsche, filled with Nitrogen stock I think ) and haven't need to deal with tire pressure, I would like to keep using Nitrogen.

I called a few local shops though, and they had no idea where I should go so I thought maybe a fellow P owner might know.

I think one suggestion from somewhere was Costco. Will check tomorrow. I'll let you guys know.

gregdacat · 09-12-2008, 02:36 AM

In the midwest we have a chain of tire stores named Tire Discounters. The one I go to tops my tires off with N2 for free. I think he sees it as an investment in getting my business when the Box needs new shoes. Don't know if you have Tire Discounters in your neck of the woods.

09-12-2008, 03:59 AM

Costco has nitrogen. They may help you in a bind. They only fill for current customers.

I have been using nitrogen since the car was new. Great for the 5 months of winter storage.

Kirk · 09-12-2008, 08:04 AM

I've been looking locally myself, but for the nitrogen reservoirs on my coilover shocks. They use a schrader valve just like your tires. Les Schwab did not have nitrogen, but they suggested the Wal-mart tire center. I called them and they were clueless. A local place (also NorCal, but not the Bay Area) called Bob's Tires has nitrogen and will fill each wheel for $7.50. I'd try some of your local tire shops.

Honestly if you're not racing the car, then I think you're wasting your money. I seriously doubt that the tires come filled with nitrogen from the factory. I've never heard this before. However, your dealer may have deflated them and refilled them with nitrogen as a "perk" for the buyer. If you're low on pressure now, fill it with air and then when you find a shop with nitrogen just have them deflate the tire and refill it.

BTW, my solution is to just buy a nitrogen bottle from a welding supply shop. I'm going at lunch today to pick one up. This way I can adjust my shock pressure to my heart's content without paying $7.50 each time. Total cost for the bottle, gauge, regulator, and schrader attachment is going to be about $200 and then ~$15 or so to refill it once a year. I may do my tires too when I start autocrossing the car.

Kirk

renzop · 09-12-2008, 09:57 AM

Air is 72% Nitrogen. There is no good reason to use pure Nitrogen for tires. Sure there are reasons, just none of them are good enough to justify the cost/hassle.

1) Nitrogen does not expand as much as it is heated as air which results in more even tire pressures but to such a small degree as to not matter (1 - 2 psi)

2) Nitrogen does not oxidize tire insides as much as air. True, but the cost of N2 fills is greater than the increased tire longevity.

3) Its terminally tech-cool. True, you got me there :-)

4) Nitrogen tire fills are a great profit maker for tire shops and dealerships interested in wallet lightening of the clientele. True, you got me there :-)

ekam · 09-12-2008, 11:03 AM

Took 7 responses for someone to point that out ...

Sorry it was a joke my mechanic told me. Some lady asked him "Can I put air in my nitrogen filled tires?"

FTD · 09-12-2008, 12:04 PM

Quote:

Originally Posted by renzop

Air is 72% Nitrogen. There is no good reason to use pure Nitrogen for tires. Sure there are reasons, just none of them are good enough to justify the cost/hassle.

1) Nitrogen does not expand as much as it is heated as air which results in more even tire pressures but to such a small degree as to not matter (1 - 2 psi)

2) Nitrogen does not oxidize tire insides as much as air. True, but the cost of N2 fills is greater than the increased tire longevity.

3) Its terminally tech-cool. True, you got me there :-)

4) Nitrogen tire fills are a great profit maker for tire shops and dealerships interested in wallet lightening of the clientele. True, you got me there :-)

I had a tire expert tell me that you have to have a certain percentage of Nitrogen to make any difference [98%?], which requires filling, deflating, refilling to get that percentage - unless you have a big honking expensive machine that does it, which he doesn't think Costco or anyone would invest in. I bet you could explain this better. And I think he said the benefits has mostly to do with leakage, which also requires consideration of the tire walls? Feel free to embellish here as well. So, overall, its a marketing attraction.

Kirk · 09-12-2008, 02:49 PM

I don't know, I think it has its place and I think there are some good reasons - but mostly as it applies to racing. Again, I've been looking into getting nitrogen myself so that I can adjust my shock reservoirs. From what I've read a lot of guys will get a 80 csf tank of nitrogen because to fill it is about $35. That one fill will last someone almost and entire season of autocrosses, track days, and light racing. They use the nitrogen for their shocks, air tools, and tires. When you're tuning a car at the track, tire pressure is a huge variable to play with to really get a car dialed in, which is checked and verified with a pyrometer. When you get to tuning a car to that degree, then yes variations of a few psi (and I think it's much greater than 1-2 psi) can be a hassle. That's where nitrogen comes into play by making the pressure more stable when going from cold to hot tires. For autocross tire pressure may be one of the only variables you can play with in relatively stock classes. So again, any advantage (using a pyrometer for setup and nitrogen for stability) may be desirable, although of course the driver is still the biggest variable!

For regular street driving... well I agree, there really isn't much of a good reason except maybe fewer stops at the gas station for air.

Quote:

Originally Posted by renzop

Air is 72% Nitrogen. There is no good reason to use pure Nitrogen for tires. Sure there are reasons, just none of them are good enough to justify the cost/hassle.

1) Nitrogen does not expand as much as it is heated as air which results in more even tire pressures but to such a small degree as to not matter (1 - 2 psi)

2) Nitrogen does not oxidize tire insides as much as air. True, but the cost of N2 fills is greater than the increased tire longevity.

3) Its terminally tech-cool. True, you got me there :-)

4) Nitrogen tire fills are a great profit maker for tire shops and dealerships interested in wallet lightening of the clientele. True, you got me there :-)

Cloudsurfer · 09-12-2008, 04:39 PM

Quote:

Originally Posted by nefarious986

It maintains pressure under heated use much better than regular oxygen. Less checking & maintenance plus some minor stuff with better mileage since your tires are always 'perfectly' inflated.

I could fill it with air, but considering I got this car 8 months ago (directly from Porsche, filled with Nitrogen stock I think ) and haven't need to deal with tire pressure, I would like to keep using Nitrogen.

I called a few local shops though, and they had no idea where I should go so I thought maybe a fellow P owner might know.

I think one suggestion from somewhere was Costco. Will check tomorrow. I'll let you guys know.

As have been pointed out, "normal" air is 72% Nitrogen. Your tires are not filled with Oxygen. I HIGHLY doubt your tires came filled with Nitrogen from the factory, or dealer for that matter.

To get into the technical side of this, we use Nitrogen in aviation due to its inert nature, on the ground here, particularly in a street car, there is practically no benefit. Maybe if you can get your tires filled for free, sure- go for it. But if you're going to pay a premium, its ridiculous, and yes, it's a fantastic profit center for any tire shop.

If you wanted to have "Nitrogen filled tires," you would first have to evacuate the air using a vacuum pump, and then pressurize with Nitrogen. I am sure no tire shops are doing this. Now, for remote reservoir shocks, its a requirement- again due to Nitrogen's inert nature, so that's a different situation.

Long story short, I would not worry about. Just use air, though preferably dry air.

Patrick

Jaxonalden · 09-12-2008, 05:52 PM

nefarious986,

As you can see from my third post that nitrogen is not worth the time or cost for the little to no benefit you'll receive. Just use free, dry air and take the money you would have spent and buy some beer and invite us over to talk cars.

gregdacat · 09-13-2008, 05:45 AM

I believe chosing to use N2 in your tires is no different than any other mod/hack. Some people like it, some don't. Some swear by desnorkling. Some say it is a waste. Some spend big buck on the stickiest tires, other say as long they last and look good, a tire is a tire. You pay your money and you make your choice.

Would I pay for N2 if it was $7.50 a tire, heck no. But I get it for free, so what is it going to hurt and it just may make a difference even if slight.

Tool Pants · 09-13-2008, 07:23 AM

Do the valves have green caps?

gregdacat · 09-13-2008, 03:19 PM

Quote:

Originally Posted by Tool Pants

Do the valves have green caps?

My wife's valve caps on her Goodyear Wranglers are green. My valve caps on my Box are black. (My request)

944boy · 09-13-2008, 04:09 PM

I think the whole nitrogen thing started because compressed Nitrogen is inherently 'dry'. Compressed air typically has moisture. Continual filling with moist air will cause condensation and the water can cause a mis-balance and rot from the inside.

All gases obey the gas-law and expand with heat.

If you are racing and constantly adjusting tires, a small bottle of nitrogen is cheap and more portable than a 12v compressor. its win-win.

Kirk · 09-13-2008, 06:30 PM

BTW, I was cruising the Harbor Freight website today and noted that they have 40 csf and 20 csf nitrogen systems specifically for filling your tires. Includes the bottle, stand, regulator, hose, and tire inflation attachment. When I was at Harbor Freight later in the day I asked out of curiosity and they said they didn't carry it at the store, so you might have to get it off the website. Just FYI.

Kirk

mookarma · 09-13-2008, 08:06 PM

If you have to have it, pull your car up to an empty operating bay (obviously don't pull it into the bay) at Costco and just ask one of the techs if you can use the hose... they won't check for a card and they always let me do it myself, takes all of 5 minutes.

nefarious986 · 09-13-2008, 09:39 PM

I got it done at Costco. I called ahead to ask and since I didn't get the tires at Costco, they can help only I removed the wheel from the car, because they couldn't pull the car into the service bay.

Haven't tried just pulling up to the service bay, but that might work too. They seems cool enough. Even gave me a free green air cap. Now people KNOW I have N2. LMAO.