Van

I agree, low tire pressure will cause the sidewalls to fail.

I vote for replacing them all.

brad@tirerack.com

That's fine. Could be several things at this point. My guess would be age and air pressure being a bit low. I would recommend doing all four at this point just to make sure what you have on there is fresh. The Sumitomos are great tires for the money. Please give me a call if I can help.

dontnow

Look at the inside of the tread portion for signs of a puncture. Like others have said, looks like it may have gotten a puncture, lost pressure and built up heat quickly.

Butters944

I'm planning on buying a set of kumho ecsta 4x's. Seem life really good tires, and affordable, might want to look into them.

http://www.tirerack.com/tires/TireSe...35&diameter=18