We were at the dealer Saturday signing the final paperwork on our order. The dealer added the Nitrogen for the tires. We called ahead and asked them to remove this. It was $70. It seemed pure profit to me. It's not like I'm going to go to the dealer every time I need a little air in the tires. The MA said that they've had customers without the nitrogen get a higher occurrence of false TPMS low pressure reports in the winter, and she said it helps the TPMS sensors. Still after trying to sell us on it, we asked to get it removed. When they did the final paperwork they threw it in for free. I guess they just use nitrogen in the tires anyway. Our dealer is about 1 mile from the house so I guess I can take it in... the service is good at anytime. So if it's free I'll take it, especially since this is really my wife's car and don't want her to have to deal with TPMS warnings.

I asked her about the spare tire. We have the 17" Cosmos Spoke wheels with run flat tires. It's not clear if we get the spare on the Justa. I assume it is standard on the Justa. I know it does not come on the MCS. I told her it looks like it was nearly impossible to get to and she mentioned the spares will not be coming on the car for long. I didn't ask further. Maybe with 2015 models they will not have any non-run flat tires???? But it seems that at some point the spare was going away. Maybe we take ours off and sell it on eBay

 

You don't really see the benefits from nitrogen filled tires until you start racing. Usually the dealer fills the tires with nitrogen during the PDI, just to add one more thing to the "extras" list (more crap to make you pay for). It would have been even more work for them to deflate and refill your tires with regular air. I don't think the spare is standard equipment on the Justa. From what I understand, the spare is included on vehicles with 15" wheels as these wheels do not include run flats. However, I think a few folks on here have reported their vehicles being equipped with a spare even though they bought the upgraded wheel packages.

 

It is standard on the Justa, regardless of any wheel option upgrades.

It isn't difficult at all and it is accessed without getting under the car. The spare is secured to the bottom of the car with a single bolt that runs up through the luggage compartment floor. From the luggage compartment, you unscrew that bolt, and the spare will lower to the ground. Full instructions are in the Owner's Manual.

 

The air that is typically pumped into tires is around 78% nitrogen (N2), 21% oxygen (O2) and 1% miscellaneous gases. Going 100% nitrogen is an advantage to drastically reducing air loss in your tires. Nitrogen molecules are larger than oxygen molecules, so leaking is great reduced. Which is why your dealer said that nitrogen is especially beneficial during the colder months (especially with TPMS). Charging $70.00 to this option is a bit high IMO. Yes, there is additional equipment needed at the dealership to store the nitrogen, but $70.00? Costco Wholesale fills all of their new tires with nitrogen. Been doing this for years. Refilling with nitrogen is always free.

Did your dealer install new valve caps? Costco installs green caps to alert dealerships and service stations that the tires are filled with nitrogen. You do not want to add regular "air" to your tires which dilutes the nitrogen and reduces the effectiveness of the nitrogen.

 

If the dealer is truly doing a nitrogen fill then they must first pull the tire down to 0psi and vacuum the air out. then refill with pure nitrogen and then you will have the slight benefits of it. I doubt they do this (maybe they fill from the factory with nitrogen, not sure) and it is to generate a few bucks. As mentioned most of the air you breath ids made up of nitrogen do the difference to go pure is minimal. If you live in a cold area then your pressure will swing less with nitrogen, but you should still be checking the air pressure in your tires regardless of what they are filled with.

If you happen to get a small nail and have the tire repaired or need to pump the tires up it will not be the end of the world to refill or top off with air and dilute the nitrogen content.

They tried to sell you with some exaggerated BS and you didn't buy it. Enjoy the car and feel good you didn't get swindled for $70.

 

Might want to read this:

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

 

And so easy to do with the computer system on our MINIs. Really handy!!

 

That's a good link, thanks!
TL;DR version for others: Nitrogen fill has benefits, but many of those benefits will only be realized on low mileage cars, as daily drivers are likely to go through tires faster than the benefits will be realized. Recommends getting nitrogen fill only if its free or no more than $5 per tire. So the $70 above is outside that range!

Also I can confirm what rkw said on Justa spare, its standard. I've got 16'' wheels with Runflats and my VIN decode still mentions an emergency spare included. (S258A = Tire with run-flat, S300A = emergency spare)

 

Nitrogen fans claim many things, better ride, no loss of pressure/no "air leaks". But scientifically the only benefit is if the truly fill the entire tire with nitrogen there won't be any moisture/water inside. If so there's less expansion/contraction/variation in pressures in the tires. That's a potential problem in Phoenix where they can get really hot. I'ts mostly profit. I don't think you will get a spare in a Justa with 17" wheels. On the R56 you only got one with 15" wheels which not many people got.

 

Consumers Report did a test of nitrogen-filled tires. They lost 1.3 PSI less than air-filled tires over the course of a year.

See http://www.consumerreports.org/cro/n...tudy/index.htm

 

True, if he adds regular air it isn't the end of the world. He'd be fine. But if he wants to continue to have the benefits of nitrogen he would then need to have the tire emptied of the air and refilled with pure nitrogen. That is one of the hassles of nitrogen usage. You must have pure nitrogen (no mix) if you want the benefits of nitrogen.

 

If you are lucky enough to get a spare - I would keep it! Down the line I plan to dispense with my run flats: harsh feel, last half as long, twice as expensive and cannot be patched for $20 - must be replaced. All so the driver can drive safely to their nearest Mini service department (+ scream when the bill arrives!) and not be inconvenienced. Seems like it's more not to inconvenience the roadside assistance crew. I think it's ridiculous! I would rather replace my own tire thanks and get tires of my choosing.
Imagine living in fear of that TPMS light going off on the console!
If I wanted to be price gouged I would have bought that CPO Boxster
PS- Nitrogen, the pros and cons is seriously nickels and dimes compared to the run flat fiasco!

 

I ditched my RFs when they wore out at about 30k miles. I just got a pump and goo and a little stabber repair kit (and AAA). Diana is right, they last about half as long and cost about twice as much. They ride a little harsher not much. Oh, and I did have my runflats repaired at Discount Tire, maybe twice. Dealers won't do it. Funny I never got a flat with the non RFs.

 

I agree with TheBigNewt. The Nitrogen molecule is actually smaller than the Oxygen molecule. 14 vs. 16 molecular weight. Both gases generally act the same to temperature and pressure (ideal gas law). Nitrogen in moisture free. It comes from a high pressure cylinder and was dried when compressed. The air is coming from a compressor that is compressing plain old atmospheric air with water. Although some water may condense out, it is not dried to the extent of notrogen. It's the water that makes the difference.

 

Note that weight and size are different things.

 

hahahahaha

the last test i read of tire pressure gauges on consumer reports said the average error of all gauges was 2 psi ... hahahahaha

the difference in loss is less than the avg error of the measuring tool


want to buy a bridge? hahahahaha

 

When I bought my car they filled it with nitrogen and they put the green cap. I thought that it was standard.

 

Wow, I didn't expect so many posts here.... I agree the nitrogen is not much if any difference to us in driving or pressure loss... but what SeabrookTX says above may be the biggest benefit. That it minimizes or eliminates moisture inside the tire and reduces the risk of corrosion on the TPMS sensors. It turns out I live pretty close to Seabrook and there is a lot of moisture in the air here, so as I suck it in my little 12v pump and compress it, it goes into my tires. I guess I should buy a water separator.

I asked the dealer what they would do when I buy new tires... they said they will replace the air with nitrogen. Probably not a perfect swap because you can't pull a vacuum on a tire, but they could swap most of it out.

Never had run-flats on a car before. The run flats on the BMW 3-series ~8 years ago were awful. I test drove that car and hated them, and didn't buy. But they have come a long way since and the Hardtop with the 17" wheels drove pretty well. Prices on run flats have come down too. And I think my local Discount Tire will repair them depending on the damage. I think getting my tires replaced at the dealership is probably not the best way to replace a tire.

 

Do nitrogen-filled tires really have only nitrogen inside them? Sounds doubtful to me as I don't see how the uncompressed air that's in the tire when it's first fitted could be removed. Typically that air will be 20-30% of the gas that's in the tire after it's inflated, so I suspect it should be called 70-80% nitrogen filling.

With the nitrogen that's in the original air, this means the oxygen content of the tire drops from about 20% to about 7%. And that makes a night-and-day difference?

 

Well... regular air is 70% nitrogen to begin with. So if you vacuum down to 20% of full, refill with 100% nitrogen, your tire will be at ~94% nitrogen level. Can do the vacuum again at that point and fill again and be at a very high 90s%. From the link posted earlier, a lot of the benefit is from reduced oxygen so reduce moisture and corrosion. May be worthwhile if your tires don't get a lot of miles on them and straight up age is a bigger factor on them than use?

 

They charge you $60 and take your car in there and put air in the tires. Then they charge you for a shot of premium tequila and put Rotgut in your marguerita. Yeah baby.

 

I'm not a nitrogen junkie (although I am a chemist and a chemical engineer by training), but FWIW attached is what looks like might be an interesting article for you science types.

http://www.getnitrogen.org/pdf/graham.pdf

Not necessarily an unbiased source, but scientifically based. Personally I'd lean toward Consumer Reports empirical findings though. I'd rather fill up the tires for 75 cents.

 

We have a Parker nitrogen machine at work.

It used a membrane barrier system to "filter" out o2 from our air compressor. It supposedly leaves the unit, and into a fill/storage tank (50 gal) at 97% pure dry nitrogen.

When running, it fills all 4 tires at once, cycled 3x, inflates, evacuates to 2 psi, re inflates, evacs again, and then a final fill based on your preset pressure.

I use it, because it's an easy way to set all 4 tires at the same time. N is just a bonus.

No way would I pay extra for it.

 

Houston, eh? Me too. Did you go to Clear Lake (Advantage) Mini? They did the nitrogen charge on me as well..

 

Yes, same dealer. I think they just add it standard to every order and hope you pay for it. But it seems in reality they fill all the tires this way anyway.