Tire pressure frustration...

[12string]

1 hour ago, ChrisL said:

AWD with traction control... My car will fix any mistakes for me!  When I got rear ended my foot slipped off the brake and I floored it by mistake trying to regain control. I’ll be damned, my car kept me from losing control AND hitting the car in front of me.

No, it won't.  If the tires can't grip the road, no amount of intervention from the car will help.  Not to mention the beating overinflated tires give the suspension components.  My first AutoX, I pumped my tires to about 60#.  I wanted the quickest sidewall reaction I could get.  Slid right off the track in the first warmup lap.  One of the veteran drivers handed me a bottle of white shoe polish.  Amazing how bad too little OR too much air can be.

Do NOT go by "eye test".  All tires are designed to actually sag a bit at correct pressure.  That's how they achieve traction and compliance with the suspension design.

Do NOT go by the sidewall.  If you read the whole thing it says "Maximum load nnnn# at nnPSI".  If you are loading the car to whatever the total of all 4 tires can handle, then you can use the number on the sidewall.

The number on the door frame is quite specifically calculated for that particular vehicle, regardless of what tire you put on it.  It is designed for the optimal performance/fuel economy tradeoff for that particular design.  There's a few pounds of wiggle room, but not too much.  I tend to run the GTI about 2 pounds higher in the front, it feels more balanced.  Except, of course, when switching to winter air.  For that, the formula is ((tire circumference/tire diameter)/pi)*summer PSI.

[Ralphie ★]

2 minutes ago, Longjohn said:

On our Honda’s the stupid pms light comes on when the pressure in one tire drops a little. I would check with a gauge and all the tires were still over 32 psi. I don’t get excited by that anymore and wait until I get home to add air. If I ignore the pms light long enough and one tire drops below 32psi the dash will indicate which tire it is.

Hmm, interesting.  From a little reading on the subject, it appears that Honda uses an indirect system, which is based on the wheel speed sensors from the antilock brakes.  Which now begs the question, what part did Faarstone replace that cost me near $100?  I guess I assumed my car used the thinghies that go in the valve stem holes, but those can measure pressure directly.  But my valve stems do look expensive.

 

[Longjohn ★]

My wheel speed sensors are encased in a thick layer of mud.

[Ralphie ★]

30 minutes ago, maddmaxx said:

The sensors can be rf and report actual pressure or they can be part of the anti skid system and report wheel speed so the master computer decides that one wheel is out of sync with the rest.....it will report the same thing if one tire is over inflated that it does when on is under inflated.

Yeah, sometimes it has been a bear to get them to reset, especially since you have to drive 20 miles or so to do that.

[ChrisL]

49 minutes ago, Bikeguy said:

I'm almost afraid to ask...   So how much tread is OK for your car?  Down to the wear bars before you replace the tie?  

Wear bars?  Are those on the door tag too?!?! 😁. 

[Ralphie ★]

47 minutes ago, Longjohn said:

If I ignore the pms light long enough and one tire drops below 32psi the dash will indicate which tire it is.

I don’t think my 2013 Civic does that. 

[Longjohn ★]

4 minutes ago, Philander Seabury said:

I don’t think my 2013 Civic does that. 

We have a 2008 and a 2012. Not sure about the 2012, it’s tires hold their pressure better.

[MickinMD ★]

6 hours ago, ChrisL said:

So my car tires indicate 44 PSI on the sidewall and every time I take it in for service they lower the pressure.

Before I got sick I had my car in for service and the tech said my tires were over inflated and they adjusted them.  I got home and you could clearly see a sag in the tires, 30 PSI.... WTF? I hadn’t been driving hardly at all the last 2 weeks but inflated them again today to 44 PSI.  

Any clue why every shop lowers my PSI well below what’s noted on the sidewall?

It's a common thing.  The little tires on my Honda Fit have a max. of 40 psi, the recommended pressure 32 psi, and the Fit Freak website says 36-37 psi is worth an extra mile per gallon without significantly making the ride more bumpy.  But every time it's serviced, it comes out at 32 and I have to raise the tire pressure.

[maddmaxx ★]

4 hours ago, Philander Seabury said:

Yeah, sometimes it has been a bear to get them to reset, especially since you have to drive 20 miles or so to do that.

There might be a reset button in the fuse box (or in one of them for some cars that have several)  In one of my cars that button also reset the service interval reminder and was supposed to be pressed by the maintenance tech at each visit.

[ChrisL]

OK so... I get it that I didn’t post any images of my saggy tires but wanted to circle back on the eye test.  You feckers who said not to trust your eyes are full of sheot!!!!

On my drive home I didn’t see a single freaking car with sagging tires to the extent my tires were sagging at 30 PSI.  They all looked like how my tires look now.

I used the Google and found this image. My tires, especially the front  looked pretty much the one below.  So do you guys drive with tires that sag like that?.

 

Maybe I’ll go skittering off the road and blow up my suspension due to over inflated tires but I ain’t changing them.

[BR46]

Before we hit the road with the motorhome Wo46 will ask if I checked the tire pressure?

Every day at the race track before the start of practice she will ask.....tire pressure good? 

It's not uncommon for her to walk into the garage, grab the tire pressure gauge and check the tires on her car and if it's 2 pounds down she will grab the air hose and put 2 pounds of air in. 

[Bikeguy]

35 minutes ago, ChrisL said:

My tires, especially the front  looked pretty much the one below.

Now I understand...

[Bikeguy]

WoBG's Honda Prelude at 32 psi.  

[Square Wheels]

I have run flats.  Hard as ef, really loud, probably doesn't add any handling to the car.  I like the idea that I can still drive on them with 0 pounds of pressure.  I don't have a spare.

[Ralphie ★]

On 12/1/2020 at 9:52 PM, Bikeguy said:

WoBG's Honda Prelude at 32 psi.  

Cool!  Great car.