Tyre Talk for all models.

[Ray]

Yes, they are black and round found at each corner. However there is a little more to them than just that as we all appreciate.
I have just come across a Flat Sixes article on Nitrogen over Air for tyre fills. There are some related posts at the foot of the page which may also make good bedtime reading.

http://flatsixes.com/porsche-products/tires-and-wheels/nitrogen-versus-compressed-air/

Regards

Ray

 

[924Srr27l]

Yes, they are black and round found at each corner. However there is a little more to them than just that as we all appreciate.
I have just come across a Flat Sixes article on Nitrogen over Air for tyre fills. There are some related posts at the foot of the page which may also make good bedtime reading.
http://flatsixes.com/porsche-products/tires-and-wheels/nitrogen-versus-compressed-air/
Regards
Ray

Yeah interesting Ray, although I think this American piece on the issues of using air in your tyres sound a lot worst than reality !

I understand the benefits for Competition use with extreme heat and the rapid expansion causing pressure increases, but in contrast to a road car completing thousands of miles over many years of use (Hopefully) this article comes across to me as a tad extreme?


Air Leakage: The molecular makeup of rubber is such that regular compressed air can permeate through the rubber allowing the pressure in your tires to drop at a rate of 1 to 2 PSI per month (assuming constant temperatures).
I note this suggests Air "CAN" Permeate, which suggests it's not for all applications ? I'm unsure if certain types of rubber used are more susceptible than others or if a Tyre's age also has an effect and older tyres are more prone to air leaking through the rubber molecules? However I can't say I've ever noticed a drop of 1 to 2 psi every month in any car I've ever owned over the last 27 years?

1. Pressure Changes: Along with the normal components of compressed air comes moisture/water and water isn't good for anything tire related. This moisture is usually a result of humidity in the air and the act of compressing it greatly increases the concentration of water by volume. Don't believe me? Try this, next time you're at a gas station and you plan on topping off your tires, depress the chuck on the hose for a few seconds with your thumb. Chance are your thumb will feel moist and you may even see water. It's this water/moisture that gets into your tire, reacts to temperature changes and can change the pressure of your tires. This is why it is always suggest you check your tire pressure "cold" before you've driven the car and heated the tires and the moisture within.

Yes some petrol station forecourt machines and the compressor's used could very well be worst than others and if there is no regular moisture release
in the tank or system the air could have a much higher content of moisture that it should do, and so hence yes regular checks are always recommended.

1. Oxidation: Oxygen corrodes aluminium and steel possibly weakening your wheels. Additionally, oxygen reacts with rubber, in a sense,"corroding” it too (possibly making your tires unsafe). Rust and dust created from this oxidation can clog valve stems, causing them to leak. Lastly, rough surfaces on wheel flanges and tire beads (due to corrosion) may not seal properly, causing additional leaks. Combine this with the moisture mentioned above and your expensive tires can possibly be damaged

Aluminium Wheels substantially corroding internally from the moisture in air?
"Possibly" weakening your wheels & Making them unsafe ? sounds very extreme ! Not to mention a Corrosive effect of rubber ! this is a new one for me?

When a Tyre's in use as it twists and absorbs road undulations and expands and contracts with temperature changes the bead area is prone to wearing away the Painted surface, which is thin anyway from the robots that Paint wheels, and over time with tyre changes etc..and the water (from the outside) getting in the crack between the tyre and rim the paint becomes so broken it leaks air.

R

 

[Ray]

I agree it seems excessive to me also for a road going vehicle. I can see the application working for racing cars due to the heat generated through constant high speeds and cornering. The cost of filling would also be a negative. Just thought I would post the article as it is informative. Not practical for road going vehicles in my opinion. Another thing would be where do you fill and top up your tyre pressures?

All new concepts need outlets. Take a look at electric and hydrogen vehicles. Charge rates and charging stations are an issue for both types of energy. Tesla owners can join a Tesla owners charging club. Whereby when you are travelling long distances you can call at a members home and recharge your vehicle, quid pro quo.

Ray

 

[924Srr27l]

I agree it seems excessive to me also for a road going vehicle. I can see the application working for racing cars due to the heat generated through constant high speeds and cornering. The cost of filling would also be a negative. Just thought I would post the article as it is informative. Not practical for road going vehicles in my opinion. Another thing would be where do you fill and top up your tyre pressures?
All new concepts need outlets. Take a look at electric and hydrogen vehicles. Charge rates and charging stations are an issue for both types of energy. Tesla owners can join a Tesla owners charging club. Whereby when you are travelling long distances you can call at a members home and recharge your vehicle, quid pro quo.
Ray

Yes it's info worth a read, I understand the theme and idea but as you say in reality things can be difficult.

I guess a compressed Canister of Hydrogen product would be too dangerous to sell an stock @ Halfords?!
A reasonable amount of Tuning shops, Outlets and Tyre fitting centres do offer Hydrogen as an up sell add on when fitting new tyres..

R

 

[graham tompkins]

Ray,
I know Nitrogen is used in aircraft tyres, and use in race cars may make some sense because of the controlled environment and equipment but road cars ????

Maybe you should change your bedtime reading . I could suggest some but I doubt your wife would approve.

Graham

 

[chrishak]

I agree it seems excessive to me also for a road going vehicle. I can see the application working for racing cars due to the heat generated through constant high speeds and cornering. The cost of filling would also be a negative. Just thought I would post the article as it is informative. Not practical for road going vehicles in my opinion. Another thing would be where do you fill and top up your tyre pressures?
All new concepts need outlets. Take a look at electric and hydrogen vehicles. Charge rates and charging stations are an issue for both types of energy. Tesla owners can join a Tesla owners charging club. Whereby when you are travelling long distances you can call at a members home and recharge your vehicle, quid pro quo.
Ray

Yes it's info worth a read, I understand the theme and idea but as you say in reality things can be difficult.

I guess a compressed Canister of Hydrogen product would be too dangerous to sell an stock @ Halfords?!
A reasonable amount of Tuning shops, Outlets and Tyre fitting centres do offer Hydrogen as an up sell add on when fitting new tyres..

R

Most, if not all, OPC's have nitrogen tyre inflation facilities. In order for it to be completely effective (and I use the term very loosly) the tyres need to be purged of all the air before being re-inflated with nitrogen, the whole exercise no doubt coming at a not inconsiderable cost.
Had mine done a couple of years ago with a complementry offer but needless to say the tyres are now inflated mainly with air...

 

[Richard_Hamilton]

Air is nearly 80% nitrogen anyway Chris, so you won't have diluted it much then.....

 

[chrishak]

Air is nearly 80% nitrogen anyway Chris, so you won't have diluted it much then.....

Good point Richard - makes the whole nitrogen-fill subject even less relevant for road cars!

 

[Ray]

This is a little off of the topic but when I did wreck diving for many years depending on depths we dived on compressed air. Some cylinder fills could be wet (high moister content) and some could be dry. Tyre's can also have wet and dry fills dependent on the compressor set up.
Most divers use scuba tanks filled with simple compressed air (filtered and dehumidified). This is safe and standard within recreational diving limits – breathing other gasses or exceeding depth/time limits requires the use of specialised gas mixtures: primarily Nitrox, Trimix and oxygen.
Nitrox, also known as ‘Enriched Air’, is a blended gas consisting of pure nitrogen and oxygen. The air we breathe normally is ~21% oxygen and ~79% nitrogen (with other trace gasses mixed in); Nitrox (generally) has an oxygen percentage between 22 and 40%.
Recreationally, diving with Enriched Air Nitrox allows longer no-decompression limits (although it restricts maximum diving depth due to oxygen toxicity) by reducing the amount of nitrogen your body absorbs, thereby reducing relative risk of decompression sickness vs comparable dives using scuba tanks filled with air.
Diving with Enriched Air Nitrox (EANx) requires special safety training, a scuba tank gas analyser and a scuba tank fill location with a compressor (and gas blender) capable of both producing and ascertaining the desired gas mixture.
Trimix is a mixture of 3 gases (nitrogen, oxygen and helium) used to increase depth limits and/or dive times. Whatever its percentages, this scuba tank gas mixture is exclusive to technical (decompression) diving: recreational divers do not use Trimix.
Scuba tank fill locations with Trimix-capable compressors must use a certified gas blender to prepare the gas mixture.

 

[chrishak]

This is a little off of the topic but when I did wreck diving for many years depending on depths we dived on compressed air. Some cylinder fills could be wet (high moister content) and some could be dry. Tyre's can also have wet and dry fills dependent on the compressor set up.
Most divers use scuba tanks filled with simple compressed air (filtered and dehumidified). This is safe and standard within recreational diving limits – breathing other gasses or exceeding depth/time limits requires the use of specialised gas mixtures: primarily Nitrox, Trimix and oxygen.
Nitrox, also known as ‘Enriched Air’, is a blended gas consisting of pure nitrogen and oxygen. The air we breathe normally is ~21% oxygen and ~79% nitrogen (with other trace gasses mixed in); Nitrox (generally) has an oxygen percentage between 22 and 40%.
Recreationally, diving with Enriched Air Nitrox allows longer no-decompression limits (although it restricts maximum diving depth due to oxygen toxicity) by reducing the amount of nitrogen your body absorbs, thereby reducing relative risk of decompression sickness vs comparable dives using scuba tanks filled with air.
Diving with Enriched Air Nitrox (EANx) requires special safety training, a scuba tank gas analyser and a scuba tank fill location with a compressor (and gas blender) capable of both producing and ascertaining the desired gas mixture.
Trimix is a mixture of 3 gases (nitrogen, oxygen and helium) used to increase depth limits and/or dive times. Whatever its percentages, this scuba tank gas mixture is exclusive to technical (decompression) diving: recreational divers do not use Trimix.
Scuba tank fill locations with Trimix-capable compressors must use a certified gas blender to prepare the gas mixture.

Arghhh, my head hurts..!