my is200, has "dunlop 9000" directional tires (cost £120 each), and lately they keep losing too much pressure??

i cant understand it? anybody else get this problem?

im havung to check the pressure twice a week and they drop from 40psi to 20psi in a week.... but funny thing is, its just the rear two (front 2 ok).

ive taken it to lexus who have checked for slow punctures etc but NOTHING !!! theyve even taken the tires off and resealed them...

....i was on the motorway and it went tottaly flat, luckly the tires are high performance so did not come off the wheel even when doing 80+mph!!...kept driving on the flat rubber till i realised happend!

i was told by lexus that they have reinfoced 'wall-like' sides ..... otherwise at that speed they would have probably torn apart....

i just want to know if this is common with lexus alloys/tires etc or if any1 else has had this problem??????

its not common, id say the tyres are not seated properly, or the valves are leaking.

i somehow dont think the dealers have done what they said they did!

I have this problem with my aftermarket wheels. Found out that the wheels had corrosion on the inside of the rim where the tyre sits. Had to clean it up with a wire brush and put a sticky black paste on it.

when i got mine changed last week the valves that were on were knackered when lexus reseated them did the change the valves?

try moving the valves from side to side to see if you can hear the air leaking. If that's the problem then try pulling then with some pliers otherwise you will need new valves.

I've had several of the valves on my Kosei wheels leak. I took the car in to my usual tyre dealer a week ago and told them another valve was leaking. They were busy so waited 1 1/2 hr for them to get to my car and they said - yes its leaking but we don't have any... (WHY didn't they tell me that at first!!?) ... and that I needed 2 new tyres. I went in on Friday to get the new valve and tyres fitted and after another long wait found they'd been sent the wrong valve and it leaks so much it can't be used. Currently running on my spare til they get hopefully the right valve tomorrow.

If you fill your tyres with Nitrogen instead of air, the leakage will be less and over a prolonged length of time. Obviously this won't fix the problem but it should make dealing with it easier until the leakage is fixed.

to Jocksuper7;

yeah they did change a valve on 1 side only tho... didnt drive car yesterday so gonna take it to filling station to c if its stopped/slowed any leakage??

if the valve is leaking its not going to make any difference