charlesatl

Last Saturday morning I took my wife and a guest out Xmas shopping. We arrived back at home at around 2 PM and I left the car parked in the driveway. It is a 2014 LexusLS L. I came back outside at 1am to take the guest home and when I started the car the tire pressure light came on indicating that the tire pressure was low. So I used my home depot car to take the guest home and returned to checkout the car.

I first thought I actually had a flat because one tire looked a little low...but when I took the tire pressure in all tires it was 27 instead of 33..so I had to air all the tires and the lights went off.

So how can this happen and has anybody else had this happen to them? It was cold here Saturday but heck I live in Southern California so its never actually cold.....just doesnt make sense that all 4 tires would lose pressure.......

sktn77a

iTrader: (2)

Actually, the most likely explanation for all 4 tires going down like that is temperature. Usually only a couple of PSI but, if you haven't inflated them for a month or so and it was hot when you last did that, then this could explain it. Do you set your tires at 33 psi cold (not driven overnight)?

dal20402

Yep, tires steadily "lose" pressure when the average temperature drops, and actually lose it if there are frequent changes in temperature. You had probably gone down slowly from 33 to 30 in warmer temperatures, and then the colder night took you down far enough to trigger TPMS.

charlesatl

Thanks guys...I thought about the temp but then again I thought southern california......again thank you.

Nospinzone

Yes, you wouldn't think it would get that cold in southern CA, but apparently it can. Here in the northeast I can easily see a 4 psi drop in colder weather. You may want to keep your tires at a little higher psi than you currently have.

NickTee

http://ffden-2.phys.uaf.edu/212_spri...ick/pvnrt.html

Kennyr44

Ok this is all way over my head but let me tell my real life experience. As a Volvo mechanic at a dealer most years the customers came in like clockwork every 5k miles because their service light came on. Along with the oil change service I would fill the tires that were almost always 5 psi low. Most people drive 1k miles a month so they would come in every 5 months. Therefore you would assume tires lose 1 psi a month. My cars at my house do the same. Since nobody checks their pressure I would air up tires to 35 psi so they would still have 30psi before I would air them back up 5 months later.

SW17LS

Yep, it was because of the low temperature.

dlbuckls10

It happened to all my tires and they lost about 7 psi. I drove from Texas to northern Arkansas where the temp dropped below freezing. My tires had nitro and this have never happen before.

roadfrog

If nitro was indeed filled in your tires, that shouldn't happen.

R Z

This is the second cold season I've had with my car. Each time around November, the light came on and Lexus put in air, reset the program and sent me on my merry way.

sdwtchlvr

iTrader: (1)

I'm in San Diego and my low tire warning triggered last week for the first time. It was my spare that had dropped a couple lbs. And my warning light was on after that. I filled up the spare a little and it went off. I parked in my driveway instead of the garage a couple nights last week and that may have been why. My regular tires were a lb or two low too.

Tec80

Nitrogen inflation makes absolutely no difference. All gases obey the ideal gas law. Plus, "regular air" is already 78% N2.