The runflats on my 2010 Golf TDI will run with very little air and its not noticeable when you look at the tire. The problem is that the tire destroys itself. I figured it was just a little low as the TPMS barked but I ignored it until my next fill up. Once removed, I saw a load of tiny rubber bits inside the tire that were once my runflats. I went about 200 miles on a partial flat and destroyed the tire with only 4K miles on it - $160 gone