do you guys check your tire pressure monitor? i've been to lexus twice to correct my tire pressure. i checked again the other day and it's steady at 32/33. i know that's the wrong pressure,,, and i've also taken into account the temp. etc. i always let the tires heat up and check and it stays steady at 32/33. and i've been doing that everyday now for a week. before i drive off the monitor may say 31/32, and sometimes it's all over the place, but after i've driven for a while it's steady at 32/33. i'm tired of going to Lexus for these minor issues. it makes you wonder if they really know what they're doing. oh well,,,, guess i'll be making another trip to Lexus. if you have to go back 2 or 3 times after buying a new car,,, okay,,, but after that it really becomes a PITA. we shouldn't be going back at all. just getting some things off my chest fellas.

 

why don't you just do it yourself then? Step 1. Go to gas station or use home compressor 2. put in air 3. done

Look at your door jam and look at what the factory suggested pressure is

 

the PSI is 35/36,,, and it was set twice buy lexus, why is the pressure always reverting back to something else and remaining there? why is it not remaining at 35/36??? could there be a problem with the wheels or tires? IDK.

 

Umm as long as they r only 1 off from each other, I c no big deal really, it happens. Ur just wasting gas in my opinion. Mines set to 40 when I got my 5k service and it's been 35-38. If its hot, sumtimes 39. But I don't c no problem. So yea. I'd stop wasting gas, it's not gonna do much just being 1 psi off.

 

The recommended tire inflation pressures are based on a "cold" tire (cold inflation pressure). A tire's effective inflation pressure increases as the tire warms up due to the expansion of the volume of air within the tire. Thus, if the tire is inflated to 35 PSI when warm, it may drop down to 32 PSI when cold. Ideally, the tire pressures would be set while the tires are cold. In this case, if the tire is inflated to 35 PSI when cold, it may increase to 38 PSI when warm.

It is possible to compensate for warm tires by adding a certain PSI value to the target (such as inflating to +3 PSI from the cold temperature). If the dealership is inflating the tires to the recommended cold inflation pressure when the tires are warm the tires will be effectively underinflated.

 

Have you tried filling it with nitrogen gas, instead of air?
I got sick of topping air every fortnight.
I fill all 5 tyres with nitrogen these days.
Nitrogen molecules are larger, so they don't leak like air.
Furthermore, your tires cruise more cool...

 

Thanx PH,,, I've considered it, I will give the nitrogen a try. I was told that nitro didn't make sense, however i am tired of the bouncy ride I get because the pressure keeps fluctuating. As far as I'm concerned the tires are under inflated and I can feel the difference in ride quality. I'll try the nitro to see how that works for me.

 

Air is 78% nitrogen.

 

Yes, air is 4/5th nitrogen.
I'm not sure why, but maybe that final 1/5th makes that difference, combined with a larger and heavier molecule, it doesn't leak as much.
The nitrogen top ups at my service station are free of charge.

Last year, I actually purchased a 12 volt automatic air pump, powered by the GS's cigarette lighter socket.
However, the home pump takes so long to pump.
The service station is so much quicker, but me and my wife must do it every month, and there is a noticeable drop in the KPa, often from 235 down to 225, or even lower, so the Dunlops wear on the outside edge prematurely all the time, costing $.

So I'll see what this nitrogen is like.
I've only had it for exactly 7 days.
It is a fraction bouncier than normal, but I have not checked if the tire technician put in exactly 235 kPa as I requested.
Often the mechanics over inflate well past the recommendations in the Lexus manual, while I personally prefer a soft cushy ride...

 

Where can you fill it with nitrogen?

 

Costco.

 

I've noticed that on mine.

When I bought the car in May, tire pressure was 35/36. Then it seems they settled at 31/32.

Just took it in for the 5,000 mile maintenance and they rotated my tires and put the PSI back to 35/36.

 

Given that nitrogen is denser and molecules are larger the ride at same psi is firmer than with air. I have noticed that on my cars with nitrogen. I have a quick home compressor so I just put air in all the car tires every 1-2 months. Not worth paying extra for nitrogen as air oxygen will escape faster than nitrogen so each consecutive filling of air will allow for more percent of nitogen to be retained in tires overtime.

 

Nitrogen tire inflation eg:
5244 W Jefferson Blvd, Los Angeles, CA 90016
4838 Sepulveda Blvd, Los Angeles, CA 90230.

 

Interesting thought but I am not sure the microscopic holes in the rubber can separate the compound known as air into it's elemental items.