Very good point. I wonder, afaik new cars don’t have tpms in the wheel, they use the abs system and rotation. Is the psi reading on the dash accurate in this case? The Jaco is very accurate, so when in doubt I use it…
That's why I check and adjust the tire pressure only in the garage in the morning. The temperature in my garage is pretty consistent with summer temperatures rarely over 70°F and winter temperatures rarely under 55°F. for those who want to be super-precise, they make temperature-compensated tire pressure gauges.
Indirect TPMS has not yet supplanted direct TPMS. None of those systems is critically accurate.
The TPMS is not meant to be used for setting and monitoring the operating tire pressure even if that's how many people use it out of ignorance. The TPMS is meant as a warning system that goes off when the tire pressure is low or too high by over 25%. I keep the tire pressure within better than 0.5 psi among all 4 tires.
Agreed that the TPMS systems are not highly accurate, but again, it doesn't need to be. I would argue a 4 or 5 psi spread among all the tires is basically meaningless for Mom's grocery getter.
Please correct me if I am wrong,...but I thought it was necessary to keep the tire pressures even, so there is even wear? Teach me if I am wrong. Also the dealership put them at 35 PSI which is what is indicated on the door jamb. I noticed an increase in gas consumption. I usually keep it at 36 PSI. Not sure why this would make such a big difference. Also I don't like the drag feeling at 35 PSI. I am so sensitive, I can even tell which tire is lower than the other.
. How much nitrogen do people think is in “air”?For everyday street driving, keeping the tires inflated to exactly the sticker stated level is not critical. A few pounds under or over is only going to matter if you are driving the car near the edge of its handling capability and in that case, the sticker rated pressure is going to almost always not be the ideal pressure. When racing, the ideal pressure will depend on the condition of the tires, the specific type of tire, ambient air temps, the temperature of the track surface, the type of track material, the type of racing, and the style of driving the driver prefers. You probably would even want different pressures from front to back or from side to side depending on the weight distribution of the car, etc. As for fuel economy, a couple of pounds lower pressure is going to make so little difference as to be lost in the statistical noise.
I purchased a device that gives me 78% nitrogen , in the privacy of my garage.
Yeah, but mine also adds 0.934% argon.
Nitrogen for passenger cars has made some people a lot of money.
You mean her SL Roadster? I've seen her put groceries in.
Nitrous, or nitrogen?
Yes there is lots of nitrogen in ambient air, so what? Using Nitrogen is all about eliminating the oxygen. Not quite sure why people refuse to understand that. It has less to do with more oxygen than it does Eliminating O2 down to a couple PSI. Eliminate to O2 and you eliminate the moisture content, and its the moisture content within the tire that contributes to the drastic changes in tire pressure. I choose the inert gas and get very little deviance in temp related pressure changes.
There is no debate among those who understand high school chemistry.
PV=nRT
That’s it.
There is a very slight difference in the rate of diffusion, and there is the matter of partial pressures in that diffusion, but most of the “debate” about nitrogen vs. air in tires is predicated on scientific ignorance.
PV=nRT is, by the way, where we get the “10 degrees F = 1 PSI”. It is the result of that equation, the universal gas law.
