The kid in the video knows enough to be dangerous.

Somebody should ask him, if he believes his theory of lower expansion with nitrogen, why he thinks that the resulting under-inflated tires at highway speeds isn't dangerous.

Ask him also that if only the oxygen leaks out and not the nitrogen, why doesn't the tire eventually end up with 100% nitrogen with subsequent top-ups?

 

I *did* say "good but not great." It's not until the end that he makes the distinction between "air" and "dry air." That should have been more clear from the beginning. Even though he glosses over details and isn't complete, he comes to a reasonable conclusion: If you're not racing, save your money.


If I were going to ask him something, it wouldn't be either of your questions. They're formulated as traps, not requests for more detailed information.

 

Traps they may be, but no worse than the false and self-serving assumptions made in support of the conclusions. I'm surprised the kid just glossed over the obvious.

- presumption that there's a consistent size and pattern of minuscule holes (porosity) in the carcass of tires that will allow oxygen to pass but not nitrogen.

False- there isn't. Rubber is an organic compound with irregular defects of all sizes. The chances that a given tire ends up with precisely the right size holes is one in a Brazilian. That's where rubber comes from so it's true.

- presumption that compressed air, even at 100% humidity, contains enough suspended moisture that it will have a meaningful effect on tire pressure.

It doesn't. The difference in pressure up to the boiling point of water (keeping in mind that this would be at close to 300*F due to the tire's air pressure) is less than typical +/- 2 psi range specified when filling them. If a tire has air inside it that at or above the boiling point of water, it's usually called 'a fire'.

The theory that contaminated compressor lines are common enough to warrant the use of nitrogen doesn't uhhh 'hold water' either.

 

....just enough factual science to support a brilliant marketing scheme to sell thousands of people a product they don't need and does nothing for them....


Dave

 

Given how heavy the F-Type is, I opted to put helium in my tires. Night and day difference. I asked my mechanic about using hydrogen as it is lighter than helium but he said he wouldn't recommend it...something about it being flammable.

 

oh...the humanity!!!

 

Tried the helium myself but it leaked into the sound system and made the meridian sound like Alvin and the Chipmunks. I think there is a TSB out on that now.

 

This is no laughing matter!

 

On the other hand, instead of a NOS system for bursts of power, just tap off some of the hydrogen from the tires.

The you could refill them with one o' them thar generator thingies that create free energy.

 

Certainly not around my garage. Whenever I yell "where's the fire extinguisher?" my wife has learned that I am not asking a rhetorical question.

 

Since it's now April 1st, I'll troll a bit. Which conclusions? The right ones or the wrong ones? The conclusion that for road use, pure nitrogen offers no advantage in performance, but disadvantage in cost seems to be the one put forth.

Porosity was largely dismissed, so details thereof were also.

Suspended moisture? Can you elaborate? Do you mean water vapor or liquid water?

I had a rough week so perhaps I'm being needlessly contentious, but if you're demanding scientific rigor you should adhere to those standards.

 

It's April 2nd, not 1st going by the time stamp of your post so the yolks on you.

You're going to make me watch the dumb video again? (sigh) The sacrifices we make in the interests of truth, justice and the Mountie always getting his man........

What I was referring to was a technique, frequently used in marketing snake oil, wherein a presenter makes a statement as though it was an accepted and indisputable fact in order to support their conclusion. Example- in the case of fuel additives, the scammer usually talks about how effective their product is in removing 'engine deposits'. Whether the product is effective or not is largely irrelevant as there are no deposits of any consequence to remove.

In the video, the presenter elaborates on the difference in molecular size (correct) but fails to do any analysis of rubber composition to support or dismiss the idea of it acting as an effective filter. By not doing so and then stating that this is not the main advantage of nitrogen, he infers that there is some truth to the concept.

He then switches to the discussion of water vapour (suspended water) of air and in particular mentions worse case scenario of a humid day at the race track. Throughout the remainder of the video, he infers that there is indeed a significant and detrimental change in pressure when using air vs. nitrogen. Please read his white board and listen to his conclusions at the 3:30 point. He clearly gives credence to the pressure change concept. A complete analysis would examine the actual variations in tire pressure at different temperatures and water vapour concentration and not just say 'it's a problem'. If there was a significant variation, given that the guy does seems to be a bright lad, he would also realize that using nitrogen would cause tires to be under inflated at highway speed since it does not expand adequately, as compared to air.

Yes he does finalize with it's not worth it from a cost point of view, but the few technical crumbs left on the table are what the deluded faint hope crowd always point to. That's why the drive-by poster dug this topic from the grave for another beating.

I hope your coming week is more pleasant than the one you've just had. I spent mine collecting about 350L of maple sap from the trees on our property, 300 of which was turned into syrup and the remaining 50 used for making a maple porter beer which should be on tap in about two weeks. If you're up this way, please stop in for a pint.

 

Local time?

There's nothing I'd enjoy more than lamenting the dearth of critical thinking in the world at large over a pint or three.

Next week should be better. We're in the middle of a shift from our old corporate overlords to new, and our workstations were migrated to the new network Monday night. My workstation was the only one in the office to not survive the migration, so for three days I was without it. Since I manage the software development infrastructure, that was a bit of a hindrance.


On the plus side, I rickrolled the entire department. Dancing Ricks on the giant monitor all day long.

 

What? How many engines have you disassembled to come to that conclusion?

 

I recently ran some engine flush through my old (110k miles) 300zx and after 10 mins of idling, drained it to find it was thick black, after running nothing but Mobil 1 for years, so...

 

Like a moth to a flame..........

Modern engines by nature of design aided by the copious amounts of very effective additives in the fuel just don't build deposits. The '50s are long gone.

 

Well, I think that's generally true, BUT w/ the advent of direct injection engines, it did rear it's ugly head again. Perhaps that's getting worked out now, but I don't know for sure.

I did have a carbon built-up issue in an Audi RS4 w/ the 4.2 V8.

Direct Injection Engines and Carbon Deposits - Engine Builder Magazine

Direct Injection Fouls Some Early Adopters - AutoObserver

 

True enough but a bottle of wizz-bang injecto-blast from the local FLAPS poured in the gas tank won't help much with that problem either.

Then there's petrified voodoo chicken bones to help with cold weather starting. $9.95 a bag, JF special price this week only.

 

LOL, well aware of that, but it's not entirely accurate to say as you did that, "the copious amounts of very effective additives in the fuel just don't build deposits. The '50s are long gone."

 

Agreed!