[smytw]

Good Morning / Afternoon..
Wondering if I could get your advice on decreasing a little the "annoyance" from my X3's TPMS on "cold" weather. I have NO2 on my tires which I thought it would decrease the tire temp and psi fluctuation with the weather temp changes in the Houston area.. but seems like it only takes half a psi or so for the TPMS to give me a tire warning, when in reality the is nothing wrong with it after manually checking tire psi... as the day warms up.. tire temp and psi go back t normal, but still the TPMS needs to be reset.

Thanks

[RhoXS]

I have had two cars (a BMW X3 and a Lexus RX-350) in upstate New York since last January. On the first cold day each experienced the TPM came on. Filling each tire to spec plus a couple pounds solved the problem. I typically run a few pounds above spec anyway because I like a harder ride, handling feels a little more precise, and it adds a bit to fuel economy.

[EvilGenius]

HA! I couldn't help but when I saw this post. NO2 in your tires? Really?

NO2 (nitrogen dioxide) is a heavy, brown, highly toxic gas.

I'm sure you mean N2, which is Nitrogen gas, which IMO putting in consumer vehicles that aren't being raced on a track an expensive gimmick that doesn't get you anything.

[RhoXS]

Originally Posted by EvilGenius

...putting in consumer vehicles that aren't being raced on a track an expensive gimmick that doesn't get you anything.

+1

I will not buy tires or services from a tire store that even suggests using N2 in tires. It is a 100% scam to generate unjustifiable sales and will do zero for you except make you the target of the tire store's disrespect when they laugh at you for being a sucker.

[pokerface]

I'm incredibly annoyed at my dealer for selling me this as well. Wouldn't surprise me if they didn't even "change out" the air from the factory and refill with N2, and it merely becomes a marketing/branding surcharge.

[Radioactive]

Originally Posted by EvilGenius

HA! I couldn't help but when I saw this post. NO2 in your tires? Really?

NO2 (nitrogen dioxide) is a heavy, brown, highly toxic gas.

I'm sure you mean N2, which is Nitrogen gas, which IMO putting in consumer vehicles that aren't being raced on a track an expensive gimmick that doesn't get you anything.

Maybe that why he has the problem!

Anyway the "air" we put in our tires is about 78% N2.

[RhoXS]

Originally Posted by Radioactive

Maybe that why he has the problem!

Anyway the "air" we put in our tires is about 78% N2.

Very good point!

[Pitiful Old Man]

I've had our TPMS complain a couple of times. The first was on one of those "cold" mornings. On checking, the tire pressures were down substantially, on the order of 10 psi. I clearly hadn't been checking the pressures as often as I should.

The second was following wheel repair at a body shop. The pressures seemed okay so I was worried about some damage incurred when dismounting/mounting the tires. However, a reset solved the problem and it has not recurred.

The TPMS reset establishes a reference pressure level. The system waits for a few miles, allowing the tires to warm a bit and the pressure to rise before setting the reference value. A variation of a half-psi from that level should not result in a warning. Tire pressures vary by a lot more than that in normal driving and weather fluctuation.

[smytw]

Lets see... so from my question I gather the following info and much appreciated advice
1. Go up a few pounds on tire pressure. Tried, seem to have solved the issue!
2. Learn to use the spellcheck (NO2) & Expensive gimmick. You are probably right, Although a one time $40 for a simple experiment wont kill me. Experimenting tweaking is what makes us love our vehicles IMO.
3. Learn my lesson. No more N2 for me... see I got it right this time!

Thanks all for the advice.

[liverman]

Tire Rack has a good tech article on the subject:
http://www.tirerack.com/tires/tirete...jsp?techid=191

The article discusses advantages and disadvantages and allows you to decide if the values are worth it to you. The final sentence of the article:
"Rather than pay extra for nitrogen, most drivers would be better off buying an accurate tire pressure gauge and checking and adjusting their tire pressures regularly."

To me, the key is a source of compressed air that is dry and clean. In Colorado with extremely low humidity, moisture in air is less of a concern than getting air at a cheap corner shop (with no filter on the compressed air line) on the beach in Galveston that may not only have water in the air, but some salt in the water. Corrosion on the TPMS components inside the tire could be an issue if you live in that climate.

[RhoXS]

Since 1969 I have owned 16 vehicles, almost all new, and averaged probably well over 100,000 miles per car (My 2002 Z3 now has 145,000 miles on it). That accounts to 1,600,000 miles (probably much more). I have never used N2 in my tires (a new Lexus supposedly came that way), walked out of tire stores that tried to sell me N2 for replacement tires, and have no intention of feeling like an AH and using N2 in the future. Not once, over all these years and miles, have I ever seen even a hint of a problem that could possibly be related to using just compressed air.

The Tire Rack article referenced in the post above is excellent.

(BTW, I have also immediately walked out of tire stores that have tried to sell me a shaving service for brand new tires to assure they were perfectly round - I haven't seen this scam recently but it seemed to be more popular when I lived in Ca in the early eighties).

[EvilGenius]

Originally Posted by RhoXS

(BTW, I have also immediately walked out of tire stores that have tried to sell me a shaving service for brand new tires to assure they were perfectly round - I haven't seen this scam recently but it seemed to be more popular when I lived in Ca in the early eighties).

Woow! Now that is a scam I've never heard before. I'm certain that would incite violence from me if anyone ever offered that to me.