Compared with Oslo, the relatively balmy clime of the Chesapeake Bay doesn't necessarily present a valid data point for this issue.

 

I live in a colder climate than Oslo. Cars stored for 4-6 months is very common here. Permanent tire flat spotting is unheard of.

 

Does Minneapolis qualify? I lived and worked a decade there. The average winter temps there are quite a bit colder than Oslo.

 

I never experienced the problem there either. When I moved from there to Minnesota is when it became an issue on a set of tires that I was never able to get to run smoothly at interstate plus speeds. I'd be happy to entertain the thought that I was mistaken regarding the root cause of this failure if someone wishes to offer up a credible source claiming that permanent flat spotting does not occur. Flat-spotting and you: how to store your tires this winter

 

I haven't seen a credible source for your theory that permanent flat-spotting is a signficant issue.

 

From the Michelin website:"If tires are on a vehicle parked for a long period, the weight of the vehicle needs to be taken off the tires by jacking it up or removing the tires. Failure to do this may cause irreversible damage".

Tire Care and Maintenance | How Do I Care For My Tires? | Michelin US

Not good enough?

 

Nope, sounds like the legal department at work as a hedge against warranty claims. All your sources are heavy on "may" or "could," when more factual wording would be "in very rare circumstances." You could also be attacked by a shark if you stick you foot in the ocean or struck by lightning if there are clouds in the sky.

We're also told by many electronic appliance manufacturers to unplug them when we leave our homes because they "could" be a fire hazard.

 

This is why I never go into the ocean, even though I live in a beach community.

 

I think increasing the tire pressure some 20%+ (to ~ 50+ psi at storage temperature) will reduce the risc of permanently damaging the tires good enough for me not to worry.

However if you store the car with normal pressure at ~ 70 F, and the temperature drops to ~ 30 F, your actuall tire storage pressure will be close to 30 psi. And that would have made me worried.

 

I knew if I mentioned my own experience with Nitrogen fill I'd start this old debate again.

Ox. makes up close to 21% of air (varies according to sources) and when replaced by the larger molecules of nitro, your tire losses air more slowly... and yes, this is the case with my vehicles and heavy equipment. Typically we do not need to add any air during the year on vehicles with a proper nitro. fill. We have checked and verified as comparison.

Ox. has moisture and nitro does not... its the moisture that expands as its heated, thus we have nascar and formula one using nitro.. at least the last time I checked. Temperature does have some affect on tire pressure, but a bit less on nitro fill.. its the overall issue of my pressure remaining constant that works for me.

Mine are filled free of charge, just to deal with the argument relative to cost and I have a couple of 'air pigs' that are full of nitro to top up if I need to.. but have found the annual change over has been the only time I've needed to add a pound or two after the tires sit all season. The nitro source needs to be of a high percent to be effective.
Lawrence.

 

I choose not to store but to drive, therefore I am.

 

Unlikely for that reason alone. From the Tire Industry Association Best Management Practices Guide for Tire Storage:

"2. If the vehicle cannot be put on blocks, the following is required:

• Tire pressure should be increased 25% from the inflation required for the loaded vehicle (ensure that the rim manufacturers
inflation capacity is not exceeded)
• Unload the vehicle so that the minimum weight is placed on the tires.
• The storage surface must be firm, clean, well-drained and reasonably level. Do not store tires in contact with black asphalt or
other heat absorbent surfaces and do not expose the tires to highly reflective surfaces such as sand or snow.
• The vehicle should be moved at least every three months to prevent flat spotting and ozone cracking at the tire sidewall flex point."

Unlike technical info drafted by federal agencies, most industry publications are crafted by experts in their respective fields rather than lawyers and politicians. This was written by tire experts, not attorneys.

 

The difference in molecular size between oxygen and nitrogen is insignificant. Even if there was a difference, there's no inherent property of rubber that makes it a consistent filter for nitrogen vs. oxygen. The 'pores' in rubber are very inconsistant in size.

But if the theory was true and only the oxygen leaked out, the contents of the tire would soon be 100% nitrogen and the leakage rate would decrease accordingly. That doesn't happen in real life.

Oxygen contains no more moisture than nitrogen. Air might have some, depending on how well the compressor and lines are looked after. The volume of water in a typical tire is insignificant and has no effect on pressure until it vapourises. Because of the pressure inside the tire, the temperature at which water vapourises is well beyond anything seen on the street.

Static cold tires pressures are formulated by the OEM using good old fashioned flaw-laden air. If the theory was true that 'nitrogen expands less', this would mean that the tires would be under inflated on the highway.

The reasons that aircraft and some racing cars use nitrogen are valid, but don't apply to street driven cars.

 

I see two business opportunities here.

1) make a device that slowly moves the car fore and aft the distance equal to the tire's circumference

2) there's plenty of unemployed champagne riddlers in France since the business is now mostly mechanized. Retrain them to become tire riddlers.

 

Nice broad sweeping generalization (AKA BS) there . . . on industry vs. government.

Discussing a subject with you is a never-ending, moving target, and you often quote out of context. We're talking remote probabilities not worth worrying about. Now you cite another source citing many more issues than permanent flat-spotting, a term not specified in your latest citation.

At least this source is more credible, and it's not a bad idea to roll a vehicle a few inches every 3 months . . . or not, and there's a 99.99% chance you'd still be OK.

 

I am willing to take the risc, and I think the risc of some permanent damage of any kind is higher everytime I (and everyone else) is out in the trafic

 

OK guys you must be right.. I'll just continue with what I'm doing as it works in the real world.
Anyway, each of us has our own way of maintaining our various vehicles.
Lawrence.

 

You mentioned before that the effects would only be apparent on tires with a very high concentration of nitrogen as source.

How does your tire shop get rid of the air that's trapped inside during installation? If it's fill/bleed/refill/repeat it's very ineffective.

If they just add nitrogen on top of the trapped air, then the concentration of the resulting mix goes from 78% (plain 'air') to the mid 80s.

Hardly worth the effort.

 

another scientifically or technically supported statement?

 

Another quote out of context? I use you as the scientific benchmark.