Wife's 05 LS has 245/45r 18 Dunlop SP 5000 Sport tires. This is probably the first car I've experienced with low profile tires. All 4 tires will loose about 1.5 lbs. of air pressure in about 2 weeks which is a little greater loss of pressure, in that short period of time, of other car tires I've dealt with. Seems like my Tundra goes several weeks without needing a little air adjustment. Is this loss about normal?

 

Does the 2005 have TPMS sensors? My SC loses air once in a while and they told me its b/c the TMPS sensors get lose at times and you have to tighten it up. You can tell by looking at the air nozzle, if it looks like a little bolt where it meets the wheel, try getting a socket and tighting it up.

 

The LS430 does not have TPMS sensors. (The car uses the ABS sensors to detect a wheel running faster (smaller diameter) than the others.) Does the car have chrome wheels that may be corroding and leaking air?

 

The finish seems to go bad, and when it does, they leak under the finish. You will need bead sealer to hopefully fix the problem, until you replace the rims for new ones.