Kwik-Fit Nitrogen ?

[jmorgan]

Yeah but it is only fun getting your own back when you can remember it.

[Hugo a Gogo]

so does each Kwik Fit have two sets of tyre inflating gear? or if you decide not to take the extra cost option, do you end up with nitrogen anyway (and not just 80%)

[PaulD86]

Two things I've never 'got' about this nitrogen in the tyres nonsense are; 1 - To the best of my knowledge no one is purging the tyre of air once it's fitted so nitrogen content will never be near 100% and more importantly; 2 -The tyre pressures written on my car I'd assume are based on them being filled with air and I would have thought that these take account for the change in pressures between when the tyres are hot or cold (they also have figures for sustained high speed driving). So my question is, if quoted pressures are for 'air' then how are you meant to know what pressure to run your nitrogen filled tyres at given it doesn't not expand with heat as much as air? I'd have thought that by setting your pressures (cold) to the air pressures recommended they could end up at sub-optimum pressure once hot. Someone can correct my physics here if I'm barking up the wrong tree.

[Fastpedeller]

Mojooo said:

I suppose the point is that by default people expect 'normal air' or whatever you want to call it and if you are being given and charged for something extra then it should be said upfront - especially as a lot of people may opt for the traditional normal air option.

The point Watchdog were making was that about 90% of those tyres filled and charged for Nitrogen (with or without prior knowledge of charge) were given AIR anyway! My point was that this is an act of deliberate FRAUD. If I paid Kwik-Fit with dud notes I'd be in for a lot of questions, If found to be doing it with knowledge probably a custodial sentence. Cuts both ways as far as I'm concerned. FRAUD with intent.

[Andyblue]

There pricing policy is quite clear.
I use Kwik Fit for all my tyres. Order online job done. Staff are polite, waiting room clean and warm with free coffee etc. Never been over charged or offered nitrogen.

[walm]

Fastpedeller said:

Mojooo said:

I suppose the point is that by default people expect 'normal air' or whatever you want to call it and if you are being given and charged for something extra then it should be said upfront - especially as a lot of people may opt for the traditional normal air option.

The point Watchdog were making was that about 90% of those tyres filled and charged for Nitrogen (with or without prior knowledge of charge) were given AIR anyway! My point was that this is an act of deliberate FRAUD. If I paid Kwik-Fit with dud notes I'd be in for a lot of questions, If found to be doing it with knowledge probably a custodial sentence. Cuts both ways as far as I'm concerned. FRAUD with intent.

PV=nRT
So for 36psi = 2.5bar you need 2.5x the volume of gas that is already in the tyre when you fit it but before pumping it up.

So effectively 1 bar is air and the next 1.5 bars is made up with pure N2 (in theory).
Of that 1 bar of air, 20% of it isn't N2.
So in the fully pressurised tyre it's 8% that isn't N2.

In other words, rather than 92% N2 they got 80% N2.

I agree it's fraud but the whole thing is a con anyway!

[anonymous-user]

Hugo a Gogo said:

so does each Kwik Fit have two sets of tyre inflating gear? or if you decide not to take the extra cost option, do you end up with nitrogen anyway (and not just 80%)

They have an air compressor. If they fill tyres with air then they feed the compressor through an inflator. I'm sure we are all familiar with that?

The same air feed is fed through a so called nitrogen generator which theoretically filters out, by some reactive process the oxygen and other gases. The 'pure' nitrogen is then stored in a receiver and used to fill the tyres with an inflation gauge.

There are also in line nitrogen generators, which work the same way but supposedly operate much more quickly and can provide 'pure' nitrogen in real time, as it were. Or so the story goes.

Neither of the systems are 100%, and unless they're properly maintained, which is unlikely IMO, they won't get better.

As for purging, the process should include inflating a deflated tyre with nitrogen, deflating it and re inflating it 2 or 3 times to gradually dilute the other gases present in the tyre. Hardly perfect even if it's actually carried out.

[mybrainhurts]

swerni said:

mybrainhurts said:

My local independent slips a £2.50 + VAT charge onto puncture repairs, without asking first.

Keep forgetting to say no beforehand.

Next time I'm going to have a pee in reception without asking for the toilet....

At your age, it's hardly going to come as a surprise to the staff

Now, look here, you...

[stewjohnst]

eatcustard said:

I was once charged for Nitrogen from Kwik Krap, I told them to get stuffed, so they took it off the bill.

Bunch of cowboys.

Did this with me too. When the Missus (well, her car) had a puncture the fastest remedy was to pop it to Kwik fit and get a new one, noticed they'd charged for nitrogen, moaned about it so they took it off. He got a bit grumpy though.

On the other hand, the time before when the other half got a puncture they did just plug it for free (different tyre).

[Drawweight]

stewjohnst said:

Did this with me too. When the Missus (well, her car) had a puncture the fastest remedy was to pop it to Kwik fit and get a new one, noticed they'd charged for nitrogen, moaned about it so they took it off. He got a bit grumpy though.

On the other hand, the time before when the other half got a puncture they did just plug it for free (different tyre).

Surely if they fill one with nitrogen e.g a puncture repair then they have to do them all being that one of the points of nitrogen is less variation of pressure at different temperatures.

[robemcdonald]

Toltec said:

Viperz888 said:

eldar said:

I prefer helium, it reduces unsprung weight, so handling is better, and the tyre squeal is more melodic.

Helium is good, but Hydrogen is better.

Radon is more fun.

Nope. Silane is what you want.

[Alucidnation]

So, how would a normal customer know for sure they have/havent got nitrogen inflation?

I know about the green caps etc, but i doubt every tyre shop uses them?

[anonymous-user]

Alucidnation said:

So, how would a normal customer know for sure they have/havent got nitrogen inflation?

I know about the green caps etc, but i doubt every tyre shop uses them?

He or she would never know.

[Fastpedeller]

Alucidnation said:

So, how would a normal customer know for sure they have/havent got nitrogen inflation?

I know about the green caps etc, but i doubt every tyre shop uses them?

On BBC Watchdog they featured a guy who was in the forensics industry (I may have that wrong), anyway he had the necessary equipment, and was curious enough to test and find he had 21% Oxygen and other gases in his tyre!

[jmorgan]

Fastpedeller said:

On BBC Watchdog they featured a guy who was in the forensics industry (I may have that wrong), anyway he had the necessary equipment, and was curious enough to test and find he had 21% Oxygen and other gases in his tyre!

He was a diver I think. But yes, had a dohicky to test the gas as his profession needs to know such stuff.

[Moonhawk]

Toltec said:

Viperz888 said:

eldar said:

I prefer helium, it reduces unsprung weight, so handling is better, and the tyre squeal is more melodic.

Helium is good, but Hydrogen is better.

Radon is more fun.

Well - you do tend to need a nuclear reaction to generate 1.21 Gigawatts.........

[Munter]

Andyblue said:

There pricing policy is quite clear.
I use Kwik Fit for all my tyres. Order online job done. Staff are polite, waiting room clean and warm with free coffee etc. Never been over charged or offered nitrogen.

Do you work for their head office or something? Because while I'm sure that's what they want people to believe it's the virtual opposite of any Kwik Fit I've been in.

"Staff are polite, waiting room clean and warm with free coffee etc."

is in reality

Staff are pushy, waiting room filthy and roasting, with a broken coffee machine etc.

Plus in the Wolves branch my brother went to, they skimmed his card. He'd only used it once. There. And a few hours later it was used abroad. (Which being a logistical impossibility the transaction got cancelled)

I'd sooner use the local "part worn" place to get a tyre in an emergency than Kwik Fit.

[Rovinghawk]

Hugo a Gogo said:

air has water vapour, which does make a big difference to expansion

The compressed air in my scuba tanks doesn't. My understanding is that it comes from a compressor.

A conclusion is that it's possible to get dry air from a compressor.

[Munter]

Rovinghawk said:

Hugo a Gogo said:

air has water vapour, which does make a big difference to expansion

The compressed air in my scuba tanks doesn't. My understanding is that it comes from a compressor.

A conclusion is that it's possible to get dry air from a compressor.

It's passed through a desiccant that removes the moisture as it go's into the compressor.

[Andyblue]

Munter said:

Andyblue said:

There pricing policy is quite clear.
I use Kwik Fit for all my tyres. Order online job done. Staff are polite, waiting room clean and warm with free coffee etc. Never been over charged or offered nitrogen.

Do you work for their head office or something? Because while I'm sure that's what they want people to believe it's the virtual opposite of any Kwik Fit I've been in.

"Staff are polite, waiting room clean and warm with free coffee etc."

is in reality

Staff are pushy, waiting room filthy and roasting, with a broken coffee machine etc.

Plus in the Wolves branch my brother went to, they skimmed his card. He'd only used it once. There. And a few hours later it was used abroad. (Which being a logistical impossibility the transaction got cancelled)

I'd sooner use the local "part worn" place to get a tyre in an emergency than Kwik Fit.

In your reality then.

I use Kwik Fit in Lancaster. No complaints at all. A few quid more than other local fitters but the pay off is mentioned above. No I don't work for them and I'm not in the trade.