new owner question Tire Pressure (NYC)

[live2ski]

So i checked my tires. they were all 34psi in a cold garage (40's). I got the car almost 3 months ago and it was in the 70's. Assuming the dealer gave me the car at 36psi, a 2psi drop with a 30 degree temp drop seems within the norm.

I'll top them off at 36psi tomorrow. This weekend I plan on going to the mountains where it will probably be below zero (f) at night. I'll report back if this worked or not. It'll also be interesting to see if altitude has any effect as there are 6000ft differences over the mt passes.

I just don't have time to check my tires every week for 1 or 2 psi. It would be good to know how the TPMS works. what is the % drop before it goes off - can this be adjusted? For folks who live in colder climates they may want a larger range to avoid the false alarms.

 

[tireboy]

tpms...

as a tire professional. i can tell you that the tpms system is the biggest peice of garbage option that auto manufacturers have invented . on a good day i deal with people that are too lazy to manually check their tire pressures . and sooner or later you wind up destroying a very expensive tire . or wind up causing an accident because of the lack of doing simple checks. do you wait till the oil light comes on before ya check it???? ahhhh no.. we have become way too dependent on electronics to tell the motoring public what to do with our cars or trucks. what happened to checking your car's fluids and tires yourself ???? all the electronics in the world cant replace the simple checks that could potentally save your life and your family....

 

[live2ski]

Sorry, I'm not much of a tire guy (or a car guy). I try to by good reliable cars that require not much more than scheduled maintenance for a long life. I'd rather fix computers. do you keep your firewall/virus/OS up-to-date daily? or do you wait for the little popup to say you need an update? same difference.

the CX-9 is the first car I've had with TPMS so I'm learning the nuances of it. I would like to have it only go off if the pressure drops x% within a specific timeframe signaling a moderate leak. Sure, over time my tires will lose some air and will need to be filled. But that can happen during other maintenance like oil changes or tire rotation.

as a tire prof, you should love tpms, as we goobs will ruin our tires easier and provide you more business

 

[jville]

Sorry, I'm not much of a tire guy (or a car guy). I try to by good reliable cars that require not much more than scheduled maintenance for a long life. I'd rather fix computers. do you keep your firewall/virus/OS up-to-date daily? or do you wait for the little popup to say you need an update? same difference.

the CX-9 is the first car I've had with TPMS so I'm learning the nuances of it. I would like to have it only go off if the pressure drops x% within a specific timeframe signaling a moderate leak. Sure, over time my tires will lose some air and will need to be filled. But that can happen during other maintenance like oil changes or tire rotation.

as a tire prof, you should love tpms, as we goobs will ruin our tires easier and provide you more business

Your both right and wrong, yes it has prospect of more business, but changing a tire with monitoring systems is a PITA! and one wrong move you just bought a new sensor (about 75$) Oh and to answer ur ? my virus software and spyware updated automatically everytime i log on(trend and webroot) and they have been good so far. I uderstand your point about u;d rather work on cars, to each his own, however back in the day you couldn't own a car without know how to do a WHOLE lot more than the turn key operations today(noy even that sometimes) I guess its mainly a POV love/hate relationship.

 

[kosh2258]

Sorry, I'm not much of a tire guy (or a car guy). I try to by good reliable cars that require not much more than scheduled maintenance for a long life. I'd rather fix computers. do you keep your firewall/virus/OS up-to-date daily? or do you wait for the little popup to say you need an update? same difference.

the CX-9 is the first car I've had with TPMS so I'm learning the nuances of it. I would like to have it only go off if the pressure drops x% within a specific timeframe signaling a moderate leak. Sure, over time my tires will lose some air and will need to be filled. But that can happen during other maintenance like oil changes or tire rotation.

as a tire prof, you should love tpms, as we goobs will ruin our tires easier and provide you more business

Checking tire pressure regularly is part of standard maintenance for any vehicle.
If you look in the owners manual Mazda recommends checking the tire pressures at each fill up, most manuals say the same thing.

Now, that said, do I check my tires at each fill up, no, I don't. But I do check them monthly, especially so in the 9 because I have the 20" tires and they aren't at all cheap to replace. So far, I haven't had to add air to the tires. But I did set pressures late last fall when the temperatures were getting down into the upper 30's and low 40's so that may have some bearing on why I haven't seen a TPMS light this winter.

Ted

 

[live2ski]

not that it matters, but I have the 18" wheels. in my case, the tpms went off in under 2 weeks of owning the car. I guess that's my bad for not checking the pressure. maybe off-topic, wouldn't keeping the tires slightly under pressure help with snow/ice traction by keeping the tire a bit softer?

 

[kosh2258]

not that it matters, but I have the 18" wheels. in my case, the tpms went off in under 2 weeks of owning the car. I guess that's my bad for not checking the pressure. maybe off-topic, wouldn't keeping the tires slightly under pressure help with snow/ice traction by keeping the tire a bit softer?

I haven't found that tire pressure makes much of a a difference in my experience (within normal limits, of course). The determining factors seem to be tread compound formulation, the tread pattern, and how much sipeing is used (sipeing is the slits in the tread - snow tires always have a lot of sipeing).

I don't mean to seem as if I'm picking on people about tire pressures and checking - not my purpose at all.
I've got prior experience with TPMS from a previous vehicle and I learned about the quirks back then. Although I do miss that system because it had a display mode that showed the sensor measured PSI of each tire and identified the low tire position. It also monitored the spare as well, which saved having to dig it out to check pressure.
The system on the Mazda, and several other brands, is pretty simplistic and not really all that useful. It meets the letter of the law but isn't worth much in terms of communicating information to the driver.

Ted

 

[todd92]

I have TPMS on 3 different vehicles and not having any problems.

 

[Craig-CX9]

Yes, I too wish that the CX-9 had the advanced TPMS sensors and monitoring. Is there an aftermarket way of reading the OEM sensors? It would be great if this could be integrated into the Scangauge!

Craig

 

[DSherwood]

I am amazed, I can look at a tire and see that it is low 2-3 lbs of air pressure, when I see a car on the road with low tire pressure, it pretty much tells me that they are unaware of a lot more than their air pressure when driving.

Of course tire pressure goes down with temperature, there is a great logical explanation from Jville. I can't believe how preventative maintenance is so taken for granted.

 

[chiurw]

I read in a car magazine that you lose approximately 1 lb of air for every 10 degF drop in temperature. Some TPMS sensors, I believe the ones installed in the Corvette, can tell you the actual pressure. However on our CX9's, these sensors are nothing more than a fancy "idiot" light. Our morning temps finally dipped into the 30's and the TPMS dummy light was on. I checked all four tires and found they were below 35 psi. Once I inflated all four to the recommended tire pressure, the dummy light was extinguished. So based on my experience, the TPMS sensors are set to trigger once the pressure drops below 35 psi, which is the recommended tire pressure. I just filled them to 38 psi to account for temp fluctuations.