Igor911

So I've noticed that if my car sits for a day or two, the first 10 mins of my ride feel like the tires had developed flat spots...

Very strange as they are still fairly new OEM tires. I've even double checked the PSI and I'm at 37/38 all around. I mentioned something to my local Lexus service dept and they claim I should do a road-force balance. My initial thought is that I don't need that since the car drives smooth after the tires warm up.

Anyone else have any experiences like such?

Joeb427

iTrader: (1)

My GS sits for a week or more and the Dunlop Sport 5100's do flatspot but are fine after a couple of highway miles.I run 32/33 air pressure.

terrycs

Could this be a cold weather thing?

Igor911

I was honestly thinking the same, maybe? Was curious as to what other members may be experiencing...

I really doubt the tires are defective...

Joeb427

iTrader: (1)

TireRack
http://www.tirerack.com/tires/tirete....jsp?techid=42

"The tread compounds and firm, nylon reinforced internal constructions used on high performance and high speed rated tires are more susceptible to flatspotting.

Heavy loads and too little air pressure in the tires (underinflation) will allow them to deflect more where they come into contact with the ground. This allows even more deflection, increasing the severity of the flatspotting.

Cold ambient temperatures make rubber compounds stiffer, increasing their tendency to flatspot."

jucytec

flat spots definitely occur more often during cold weather... but shouldn't occur if the car is kept in the garage...

but.. 37/38??!! way too high! bring it down to 33±1.

Rexus300

iTrader: (1)

Its flat spots and everyone gets it. Some cars more sensitive then others and certain brand of tires more then others. Michelins flat spot less the dunlops and Bridgestone for sure but nonetheless do flat spot. Your tire pressure is too high! My f sport would vibrate so much more with those pressure when car sits for a day in cold. When I brought it down to 33 psi its smooth even when car sat for a while. The higher pressure will amplify the flat spot more and the gs sedan will sense it so drop pressure to where its supppse to be.

Joeb427

iTrader: (1)

I still get a bit of flat spotting after a week or so in the garage in warmer months.Attached garage but does get a bit chilly in winter and worse flat spotting that takes longer for tires to get normal..