I have been meaning to post this for a while now. I like to keep my tire pressure on point due to handling and mpg reasons. Since this car has a useful pressure monitor (which overstates the psi), we can see the exact pressure in all the tires.

I have been noticing that both the front and rear driver's side tires deflate considerably faster than the passenger side. Around 4 psi each over the course of a month.

Anyone experience this and know the reason? Is it the extra weight of the driver?

 

i hope you're checking your pressure at the same time in the morning, before your first drive, to compare your readings. your psi can go up as much as 4-5 psi just from driving it.

 

^ that.

something similar happened to me, except it was only one wheel that was decreasing a bit faster than the other. got it checked out and turned out there was a nail in there.

 

4psi/month is high. Maybe you have a slow leak?

 

i've got a nail in my back right one, but as of now its not leaking air(been in there a good 2 months atleast lol). after the roads improve a bit i'll have it repaired. tire coverage ftw

 

I agree. If you're losing 4 lbs a month, there's a problem (it is a good practice to check often, but..... it shouldn't really go down at all, even this time of year). It's odd that each one goes down by the same amount (right?). I have a problem with one of my wife's tires (it loses pressure intermittently, sometimes allot), I can't find anything in it, and I'm starting to suspect the TPMS valve stem unit. I wonder if these are going to start showing up as a problem?

 

It's your fat ass creating more pressure in the tires on your drivers side, which accelerates the slow leaks you clearly have in your tires.

 

I'm pretty sure the tires don't have holes. And yes, I know to check the cold pressure. I don't believe its because of my weight, being that I only weigh around 170lbs. Still a mystery... Maybe it is the valve stems like simba said.

 

I don't recall that my tires ever have 4psi difference, 2, yes, but not 4.
They consistently show at 32

 

How accurate are the monitors? I swear I sent my tires to 35 with a trusty gauge and not all show 35. Is there a reset procedure for them? On my Wife's Mini there was a button you had to hold down to "re-sync" after changing any pressure.

 

Could also be leaking from the tire/rim interface due to corrosion. You can try spraying soapy water on the valve stem and other suspect areas to try to pinpoint the leak.

 

in the morning, in my parking lot,
the sunlight shine only right side.
when I turn on the engine, right side tires' air pressure is little bit
higher than left side,,,,

maybe this kinda related??