ColinB

When I had my last set of tyres fitted I was offered a Nitrogen fill. Free, wow!

'No thanks' I said, I'll stick with the regular stuff. (Same price too). Privately I thought "this is nonsense, just a sales gimmick to get me hooked on Go-Faster Nitrogen"

Now, I know that race cars use Nitrogen and it has advantages of cooling amongst others but unless one is interested in the last ounce of performance is there ANY advantage in Nitrogen on a road car. Methinks not. After all, air is already 80% Nitrogen.

Insight anybody?

Colin. 89GT.

sendarius

It's not just the nitrogen, it's the fact that it is DRY.

They tell me that the delta in pressure due to delta in temperature is lower as a result.

Sharkbody

They should be filled 2 or 3 times to minimize residual moisture and O2. Ditto on the delta stuff. Helium might be interesting. G

ColinB

OK guys
I buy the advantage of dry gas but any air compressor could be equipped with a dryer/vapour trap and achieve the same. If Nitrogen isn't just a gimmick there has to be more to it.

I'd like to lose 1000lbs of weight with Helium too George. But it's expensive and has a nasty habit of sneaking it's molecules through the tiniest of gaps.

Colin. 89GT

Sharkbody

I recall the offer was free. Give it a whirl. G

GUMBALL

That is the point to it - some air compressors do not have a drier/vapor trap, of the ones that do, many are not serviced regularly. The question with ANY compressor is "how much water vapor"....

Bottled nitrogen has a maximum of 6 ppm (parts per million) water vapor.

dr bob

MOst compressors are equipped with water traps, but they only remove droplets that are entrained in the air flow. Vapor goes right through. To get the air as dry as the nitrogen, you need at least a dessicant-type drier, and prefereably a regenerating type.

The differences between dry and not-so-dry air won't be noticed at all in normal street driving unless you check your tires with a gauge. On a race car, where you are fine-tuning the suspension with a pound or two of air, it will be more noticeable. Race tires tend to run a bit hotter than street tires anyway, so the effects of moisture in the air would be greater. No matter what "dry" gas you choose to use in the tires, it will take several fill/purge cycles to get residual moisture out of the tire, and even then it won't be moisture-free by any stretch.

On the helium idea, good deal if you can get it to stay inside the tire. Like a giant latex balloon, tires are not quite airtight enough to hold helium for any length of time. Helium is a pretty small molecule and manages to find its way through places where air can't quite squeeze through.

Imo000

DELTA Sure makes a simple answer sound complicated. Just use the word "difference" and everyone will understand it.

dr bob

I think "change" is probably next appropriate word here, but after "delta". Too much Catholic education, then too much process engineering, then too much...

RyanPerrella

nitrogen molecules are also larger then air, so there is less pressure drop over time due to air escaping.

If its free, do it

Ed Hughes

Delta is less letters to type than difference. He's conserving server space.

Go with the Nitrogen if it's free, making it a no-brainer...

ritzblitz

I bet you could save a pound or two filling the tires with helium.

dr bob

Air, as most of use know it anyway, is about 78% nitrogen. Maybe if the other molecules leak out, they'll leave just the N2 atoms in there. We really just need to get the water and water vapor out. The pure gases all pretty much subscribe to that pv=nrt idea.

ColinB

For those who offered the "If it's free, go for it" suggestion. Well you're right of course. Nothing lost that way, but it was only the FIRST fill that was free. Thereafter if I needed to top up I'd have had to pay (and drive miles to a Nitrogen vendor too.) Now to me THAT's a no-brainer.

I stand by my original equation. N2 = BS

Colin. 89GT

mark kibort

you have got to be kidding

I use NOS to fill my tires. its better than air, as i do have the advantages of it being dry, but im not concerned with the pressure rise as i know what pressures to set to before a track session to get to the correct pressure due to heat. the nitrogen will give less of a pressure rise spread due to it being dry and being without the water vapor. however to really use it you need to fill the tires at least 3 full times to get near 90% pure nitrogen in the tires.

at 30psi, its only 2 atm over an empty tire. so, you still have the volume in an empty tire to deal with. anyway, the weight of a 2 atmospheres greater in a tire is measured in near ounces, so using helium wouldnt save that much.

Mk

so,