I am thinking of getting a tire pressure monitoring system (TPMS) and want to know which brands and models are good or bad.
Do you use just the TPMS alone to monitor the tires, or do you still use a tire gauge to check pressures?
I find my tire pressures are down a couple of psi every two or three months, and don't know if this is seepage or loss due to my taking pressure readings. If it is from seepage, I wonder if using nitrogen gas instead of air would help.
Tom: I have pressure pro and have used them for about 3 years. I always ck my tire pressure with this unit. I do not remove them and ck with a gauge. This allows me to monitor the tire cold and then what the pressure is hot. I find knowing the tow tire pressure is reassuring. I watch these pressures throughout the day. I have no issues with removing the units from the tow when the coach is in storage. DAN
Tom,
I have Pressure Pros but would not buy them again. Yes, they have saved us some serious losses and for that we are truly grateful. But there are now better systems on the market. What I did was buy a very good quality tire gauge. I think it was around $30 and was made in America. I had Discount tires check the accuracy of the gauge and it was dead on the mark. Next I took the Pressure Pro monitor reading for each tire and checked it against my gauge. This takes patience and time to do. Keep in mind that the time of day and the ambient temperature will give you different readings -- especially from sunny side to shady side of your coach. I found that there is a 3 psi difference between the Pressure Pro monitor and my gauge. So now while I can feel comfortable reading the PP monitor, I rely on my gauge to fill to the target pressure.
Hope this helps.
Tom,
I bought a TST system for my SOB. The weight of the sensors on the stems caused grommets to fail on two tires. The grommets were probably a few years old. The system was not reliable in subfreezing temperatures. The system is all in a box somewhere in my home. I currently check tires with a gauge, a 1/2" break over driver (wrench for thumping), and an IR thermometer.
The FT came with Pressure Pro on the coach and toad. The toad flatted one tire twice during the few days I was inspecting the coach and toad. After we removed the PP, the toad never flatted again.
Immediately after we bought the FT, we purchased new tires. Herman Power tire company put the PP sensors on the new tires. One of the new tires flatted before we picked up the coach. We removed the PP and it is in a box somewhere on my premises. Tire pressures have remained consistent for 16 months as measured with a dial gauge. There is a drop of about 1 psi/month, but the biggest changes are due to seasonal changes in ambient temperatures.
From what I have read and from my experience, losing about 1 psi/month is normal. The air we breathe is about 78% nitrogen. I would not expect "filling with nitrogen" to provide any benefits other than psychological. That is strictly my opinion, other opinions are likely to be different. Sellers of nitrogen filling system would definitely tell a different story. My opinion is based on experience and what I learned about gasses in science classes.
I especially check pressures when ambient temperatures are low. I check during the coldest part of the day when the coach has not moved for several hours. I make sure that my tire pressures meet minimum "cold" requirements according to manufacturer's recommendations for axle weight.
As always, opinions and recommendations will vary
One thing I do when I remove the Pressure Pro and put it back on I put the stuff(?) that came with the unit on the stem. I think it is to keep the pressure pro from sticking to the stem. I have not lost air from using the pressure pros so far. Herman Powers also installed my tires and before I put the pressure pro on the tires I had a flat. Powers came and put in a new stem. So far so good. DAN
Found this. http://www.getnitrogen.org/pdf/graham.pdf (http://www.getnitrogen.org/pdf/graham.pdf) and this Nitrogen in Tires : Information about Nitrogen Tire Inflation News, Benefits, (http://getnitrogen.org/why/) . I always thought that nitrogen was used in commercial aircraft to prevent explosions when the tire gets really hot from a max effort stop. Large aircraft wheels also have fusible plugs that melt and deflate the tire when it gets too hot. Having said that I use the on-board air that has gone through the dryer to top off the tire pressure. It's usually several months before I have to add air. Suspect I lose more air checking the pressure than any other way.
I would check to be sure that you can adequately hear the alarm when it sounds.
My Pressure Pro units are at a frequency that I can barely hear it, especially when the drivers side window is open.
They could have done a much better job with the alarm.
Regards,
Another point of view on the subject of nitrogen in tires.
There is a lot of marketing, but few references to support using nitrogen in tires.
We are already running nearly 80% nitrogen with air. Nitrogen's properties are not much different than oxygen.
If temperature increases, either pressure or volume (or both) must increase.
The primary reason nitrogen is used by the military is because it is inert. It will not promote corrosion and it poses no combustion hazard. Keep in mind that the SR-71 runs at 600psi. A blown tire in a wheel well with hot brakes and with the blow tire taking out the brake lines could fan a serious fire. Nitrogen will quench it.
If low humidity were the issue, it would be much cheaper to use moisture separators and filter stacks
Nitrogen inflation is NOT a bad thing, but it's not a big deal. If the shop uses nitrogen, it's fine. It's not worth paying extra for. There's a lot of hype, voodoo, and misinformation.
One thing about topups... TRY to get your air at full-service stations, rather than the coin-op units at gas-only or gas/quickie mart stations. The full-service stations also run their tools and other equipment from that compressor, so they are more likely to drain the tanks every night and deliver dryer air. Who knows how well the coin-op units are maintained. .
Well, after all this talk about pressure pro not reading correctly I decided to ck. You are correct The gauge saids 100 and the pro saids 92. They all read a little different than the gauge. I just got a new quality truck gauge so it should be correct. When the tires get hot the pro indicates about a 10 psi increase. Thats ok as long as it always reads what it thinks the tire psi is. But u need to know the definition of the word"is" is. DAN
I think the definition of "is" is as follows.
Set tire pressure to the desired amount. This obviously cannot be done using PP. Use a tire gauge you believe in (aka, have faith in). Whether it really is "accurate" is subject to verification by means other than its brand or provenance.
Then with PP on tires see if/how/when its readings change. PP does not need to be "accurate" It just needs to be "adequate."
"Adequate" means reasonably reflect pressure changes.
In below the operative word is "should" ;o)
best, paul
Karma to you Paul Thats my thinking also. DAN
I just installed the TST monitors a week ago after setting the pressure with my gauge. The monitors gave me within a lb the same pressure reading so we will see how it lasts.
So far so good
John
I don't use a tire monitoring system so I can't speak to their advantages. But I do have a good tire gauge with a 180 Degree head on it so that I can easily reach the inboard tire stems. As an accuracy check I periodically run by a tire store that I have used for years and check my gauge against their calibrated one. They tell me that their corporate folks require monthly calibration so that is good enough for me.
Gary B
( I have found that my gauge reads 2 pound high compared to theirs. )
Alcoa sells a very nice 180 degree reverse gauge. It is the only one I have found that will work in my little wheel holes. One of the few you can find on the net.