Has tire pressure changed with TPMS?

For most of my driving life, my tires had 2 states of being: OK or flat. If a tire was flat, you added air or had it repaired. Other than that, you just drove on your tires and never thought about air pressure. I remember going years without ever adjusting my tire pressures. 

Now that all of my cars have TPMS and digital readouts and warnings, and I have mobile air pumps from autocrossing, I am always adjusting my tire pressures to maintain ideal performance and wear. Odd how tires used to maintain pressures forever, but with the advent of TPMS, they started fluctuating wildly. Weird.  

I set mine to the door numbers when I do an oil change and ignore them. If the TPMS idiot light is on, I ignore it as well. I'm not going to change or reset the tire pressure every time the temperature changes. 

pinchvalve (Forum Supporter) said:Odd how tires used to maintain pressures forever, but with the advent of TPMS, they started fluctuating wildly. Weird.  

I think we just ignored them before and they were perpetually low.

When I worked for the dealer it was amazing how many cars are riding around with the light on. Also working research and development for a large tire company it's interesting seeing the OE/consumer data of how many people try to warranty tires that have been run flat/low for a long time.

I've always checked regularly. Winter always had to add a few, summer drop a few.

You used to see cars with half-flat tires everywhere. Now with TPMS there is always somebody at the free air station. It's a good thing. Prevent a lot of accidents.

It's amusing though to see a line at the gas station for air when a cold front hits.

pinchvalve (Forum Supporter) said:

Odd how tires used to maintain pressures forever, but with the advent of TPMS, they started fluctuating wildly. 

They didn't.  The seal isn't perfect and eventually tires will need to be topped off.  But it never used to bother us if they were 1,2 or 5 psi low, because we never knew.  I recall having to check my tires on my daily with a pressure gauge every once in a while.  Now I never do that until I get a warning light, which with my old E36 M3ty tires happened about once a year.

And yes temp change impacts it as well.

I try to keep track, say quarterly.  If the TPMS light comes on, it's usually time I checked it anyway, so I do.

Bought a used car from my sister.  There were service records for oil changes like clockwork, every 3000 miles.

I don't think all 4 tires had 100 psi in them put together.

TPMS is a good thing, I'd rather have people worried about that light and checking/adding air as needed for the sake of safety and handling. Proper ride quality and MPG are bonuses. My parents aren't the best at keeping up with maintenance sometimes but they will check tires if that light comes on. Before TPMS? Probably not unless the tire looked flat, which means you've been driving around way low for a bit.

I hate dash lights so I deal with pressures if the light comes on. The Cayenne can tell me per-tire so I scroll the dash to that screen every so often and check it quickly anyway.

We checked our Civic's pressures a month ago because we got a TPMS warning. Set them back to stock.

My wife is heading out of town today, so we checked the pressures again last night.

They were all 1.5 psi low. That's not nothing but it's something. 

pinchvalve (Forum Supporter) said:

For most of my driving life, my tires had 2 states of being: OK or flat. If a tire was flat, you added air or had it repaired. Other than that, you just drove on your tires and never thought about air pressure. I remember going years without ever adjusting my tire pressures. 

Now that all of my cars have TPMS and digital readouts and warnings, and I have mobile air pumps from autocrossing, I am always adjusting my tire pressures to maintain ideal performance and wear. Odd how tires used to maintain pressures forever, but with the advent of TPMS, they started fluctuating wildly. Weird.  

It was that wild fluctuation that was causing accidents. Thus the actual reason for TMPS being implemented.

If I get a TPMS light, I check pressures. Chances are something's wrong. Waiting for the next oil change can mean destroying a tire via a flat or at the very least degraded handling and increased tire wear.

dculberson said:

pinchvalve (Forum Supporter) said:Odd how tires used to maintain pressures forever, but with the advent of TPMS, they started fluctuating wildly. Weird.  

I think we just ignored them before and they were perpetually low.

Exactly this.  TPMS just makes us aware when tire pressure inevitably drops, due either to a puncture, or the gradual loss as air molecules seek to reduce the pressure in their stressful lives by escaping the tire.

I will always overinflate my tires by 5 psi or so over the manufacturer's recommendation.  This way, after a year, the average pressure will be about right.  Unless you check and adjust it very frequently, your pressure will always be below the manufacturer's recommendation if you never inflate them over that number.

Let's not forget that the reason TPMS became a big thing at all is that people were driving Explorers with tires that didn't look low and rolling them.

YIL that a Honda Fit with 9psi in a rear tire looks normal.

Shadeux said:

You used to see cars with half-flat tires everywhere. Now with TPMS there is always somebody at the free air station. It's a good thing. Prevent a lot of accidents.

It's amusing though to see a line at the gas station for air when a cold front hits.

What is this mythical free air station of which you speak? 

I picked up my wheels a couple of weeks ago, noticed the front left on the better half's car was low. I had to hit 5 gas stations to find a working a pump, and got a fraud warning on my credit card after the 3rd station because they all charged $2.50+ for air. 

When we first picked up the Corolla, the tires all matched and were quite new and looked fine.  After a drive, I'm like, "this thing handles like it's on marshmallows."  It would let out a little squeal around corners that the CX-9 would zip right around without drama.  When I checked the tire pressure, I found that 3 were at 18 psi, and one was at 25.  I've got them all around 35 now, and it's like a different car.

i hate tpms. Wife's car currently has no sensors in the wheels. But before that has a fault in one of the pickup points because the work fine on my car, so the sensors and pressures were correct. Don't have a scanner to find out which one or what is dead so it just stays on. Annoying to say the least. I always check hers about every other week anyway. Rear tires never look flat on ours until they are at 2-3 psi

In reply to z31maniac :

Really? 'Cause there's free air here.  We've been bombarded with Wawa and Racetrack stations. My local convenience store took their coin operated one out after it broke. No point in fixing it.

I know what station locally has free air if I want it - one of the Conocos, but not all of the Conocos. But I also plumbed a small compressor into my garage so I can easily top up tires :) The E39 M5 has a slow leak in one corner that I think is a porous wheel, but with those low profile tires you'll never see the low pressure unless you check. The TPMS reminds me if I don't stay on top of it, and the plumbed in compressor means I really don't have an excuse.

I used to check every two weeks or so, and air up as needed, back when free air was more common.  Now with TPMS, I tend to let it slide until either the light comes on, I'm doing some other work on the car, or am about to take a long trip.

It's not ideal, either, I have three cars that predate TPMS, and have gotten lazy about checking pressure in them, too.

I like TPMS but I hate sensors inside the wheels. It's just a way of illuminating an irritating warning light that I have no ability to rectify until either removing the bulb or fixing the overly expensive sensors. 

I have debated trying to break the bead on my truck's tires in order to pull the sensors out without paying anyone, but something that tells me that'd be a losing affair. 

I'm pretty happy with the various cars we've had with TPMS. There seems to be perpetual construction where we live and the wife's car occasionally picks up a nail. In fact it just happened over the weekend. Without the TPMS there's a chance we would have driven on it and destroyed the tire. Instead we just needed a quick patch. 

Back at the used car dealership I would spend somewhere around 60 hours a year dicking with tpms issues. We had between fifteen and thirty five cars on the lot at anyone time. 

In Wisconsin the temperature can swing drastically and affect the tire pressures. 

One older lady sat in her car and honked the horn for five minutes till we went side and approached the car. She refused to roll down the window or get out of the car. Just yelled at the top of her lungs about her low tire light. It was January and -15 with 40mph winds. 

Be a grown up and check and adjust your tire pressures. Just like people have been doing for a hundred years.(Not directed at anyone, just shouting into the void)

Pete. (l33t FS) said:

YIL that a Honda Fit with 9psi in a rear tire looks normal.

Yup, seen similar myself.

Something about street tire pressures from our friends at Tire Rack right here.