I think nitrogen used in car tires is rather gimmicky. I say this based upon two reasons.

First, I am in the aviation field, and we use nitrogen in aircraft tires. The main reason is to prevent corrosion of wheel assemblies, nitrogen will have virtually no moisture compared to compressed atmosphere.

Second, in motorcycle tires, you set a cold pressure which is based upon the expansion of tires as they heat, and so a cold PSI will increase as the tires get heat in them. Tires need to operate in a specific heat range, and pressure is used to manipulate the temperature, and therefore grip.

I don't think either variable applies. I actually have a nitrogen generator and a laser temperature gauge, and could experiment with temperature fluctuation and PSI differences. I really doubt it would make much difference at anything but a 10/10ths application.

 

I settled for 41 or 42 psi in the Michelins with nitrogen. I still prefer nitrogen although I think it heats up slower than air.

I compare the nitrogen to a breaker-less ignition. No adjustment for about 100,000 miles or more. That saves gas.

Tires with air tend to loose about a pound over a month or so. If you don't air them back up you end up with a 28 to 30 psi cold tire. That lowers the gas mileage and puts extra wear on the tire.

With nitrogen im finding I don't have to add any more. It seems to be stable so I may just check them in the spring and fall to see if they are ok. To me in the long run would save a little gas.

I had some cheaper brands of tires in the 70's that I had to add 2 psi ever month to all four tires.

I mentioned ignitions. GM prefected their long duration 80K single spark in the late 70's. Starting in 1990, GM had a magneto type that fired two spark coils from the crankshaft. The ECU somehow maintained the timing. Toyota in 2003 started with the coil over plug ignition controlled by the ECU. The spark advance can be changed for each cylinder due to the reading from that cylinders knock sensor. What an advancement this is over the last 30 years.
I'm sure all our Camry and Prius Hybrids use this last method.

 

When you replaced your tires, did you replace the valve stem also? For the rubber style valve stems, I routinely replaced the valve stem along with a tire replacement.

 

No no need to replace them. My TCH only had 22,000 miles on it October 2009. That's when I put the new set of michelin saver tires on it.

 

These cars have TPMS sensors that take the place of a normal valve stem. If you want to replace them, it will cost you better than $300 for the set (OEM) plus getting the computer reprogrammed to recognise them.

 

The valve stem sensor and battery must be made as one unit. I read the batteries last for 5 to 7 years. Another site says 8 to 9 years. I think the TCH uses the stem type. Their is another type sensor that's strapped to the inside of the wheel using a band.

I had my tires rotated and balanced and walmart. The service writer ask me to pay $20 to reprogram the sensors. I said no way. Before leaving I did press the button in the glove compartment just to make sure the light did not come on. Now with nitrogen I have them write, not to touch the tire pressure on the order. I keep my tires around 41 psi cold or at dusk, which is now easier using nitrogen.

If I have a flat the warning (i) lamp would come on. Not sure if the display would read correctly front or rear tire. If I get the warning I would sure pull over to the shoulder for safety.

It would be high to replace the sensors so the light wold stay off when the car gets old. Also they would have to reprogram them. I hoping I can trade to a new model before that time comes.

 

Thanks for the information about the valve stem being part of the TPMS. Anyone have experinece with having to replace a TPMS sensor?

 

OK,

On the TCH, your sensors are not tied to any position on the car. The warning light will come on when any one of the 4 sensors detects a low-pressure situation. You can rotate and or replace the tires at will and they do not need to be "reprogrammed". They are registered to the car however and if they are replaced, the new sensor will need to be registered with the monitoring system.

The TCH is capable of registering 5 sensors but the space saver tire does not have a sensor because of the much higher pressure that those tires run. By the time the warning light came on for the spare tire, it would be dangerously low in pressure. If you replace the space saver tire with a standard rim and tire however, you can add another sensor and register it.

It does take a bi-directional diagnostic tool (factory system or something like that Snap-on Modis or Verus) or a dedicated TPMS scan tool to register a new sensor to the car. It is not something you can do without them. If you have the tools however, you can buy new sensors, have them installed in the wheel of your winter tires and just re-register all 4 sensors every time you change tires for the seasons.

If you come across another “service writer” at Wal-Mart that wants to “reprogram” your sensors after rotating the tires or replacing them, turn him in as he is either incompetent or ignorant of how they work and needs to be educated or he is a crook padding his pocket. Either way, the management needs to correct the problem.

 

By the time for my next rotate and balance at walmart in early 2010, they had stopped asking for the re-registering price. Evident most cars have the low tire warning, and don't necessarily point out which tire is low. That's fine with me as long as I know I got a low tire. It's easy to overheat and ruin a tire that's going flat at highway speeds.

 

replaced my tires with Khumo Platinum LX's and they are fabulous! Not a LRR tire, but get the same mileage by watching the pressures more carefully and they cost about half!

HIGHLY RECOMMEND THESE!