I was just cleaning my 2022 Lexus RX 350 (I bought it 2 weeks ago) and I noticed that the caps on the air valves on the wheels (all 4 have them) have a writing on them a blue N F with a white background ....
Does anyone knows the meaning or the reason for this?... this caps are metal ...some one mentioned "the those wheels do not have air but some nitrous gas" ... never paid for that and the RX had just arrived on a truck the day I bought it...
I am sure someone has an answer .... thanks

 

NF could mean Nitrogen Filled. The local Costcos here usually fill the tires with Nitrogen; your dealer might have done the same. Is it just a sticker with the NF on it, or actually embossed/engraved into the caps?

 

..it is embossed/engraved on the cap (they look very nice white background nicely stenciled letter N F ..... further more, I had a 3 inch screw in one rear tire 3 days after I got the car, took to a tire place, the pulled the long screw, patched the flat properly, put the wheel back on and never mentioned anything. Days later I noticed that the tire on the left front alarmed as "low pressure" and I did fill with more air..that is when I noticed the valve cap....if the tires a filled with nitrogen, did I did something wrong by adding regular air?...
Like I said I saw the car unload from the truck.. I doubt the dealer filled the tires with nitro..uhmmm....the plot thickens...lol

 

It's possible that the caps were put on a long time ago, and that the tyres are no longer filled with nitrogen. Either way it doesn't matter if you add regular air.

 

You didn’t hurt anything. Both of mine supposedly had Nitrogen filled tires that they wanted to charge for. In both cases I refused to pay for it and have used nothing but air from my compressor to adjust as needed. Everything is still working great.

 

Remember that 78% of the air we breathe is nitrogen. For race cars you'd want nitrogen. Less pressure increase as tires get hot and it's less likely to leak out than air. It's nothing but another way to lighten your wallet. Air in passenger cars is just fine.