All the non OEM tires I have seen in the stock 215-50-17 size, except the Toyo TPT's, have had a load rating of less than 93. Does this have anything to do with the "flat spotting" people are complaining of?

 

I had Nittos for 3 years with Lrating of 91 and no problem what so ever...

I will be on 95W soon.

 

I run Kumho ASX 235/45's 93W's and I think my flatspotting was due underinflation (max inflation of 51). The installer had them at 34 which is only ~60% of max (underinflated). Now that I have them at 41, which is still only 80% and borderline, there is no problem. I think it is inflation more than anything. Otherwise I am happy with this tire.

The new Yoko Avid V4 and the Dunlop SP Sport A2's are also at least 93 rated in stock size.

 

Some tires just have problems with "flat spotting."

I've got Toyo T1S and have never had a problem with them.

Other brands use different materials and construction; some of them get a lot of complaints from owners...

 

Nylon cord tires flat spot more than steel cord, both smooth out when they get warm.

Other than being the max the tire can take, the pressure limit shown on the side of the tire has nothing to do with how much air to put in. What Acura put on the door post is a lot better starting point.

The best pressure depends on the tire, the car and the way it's driven.

 

Flat spots are caused by two things. 1) Locking the tire under braking, thereby scrubbing rubber off the tire at the contact patch creating an unbalanced tire. 2) Parking the car in one place, without moving it, for an extended (read months) period of time. Some brands are more prone to this than others.

Load ratings and tire pressure have nothing to do with it.

 

I have Kumho MXs with a load rating of 94. They flat spot like crazy overnight when it's cold out. I think it has more to do with the construcion and performance catagory of tire they are. I think with race rubber you're not supposed to let the car sit on the tires for any extended periods.