In firaly new tires, driving gently for 20 miles or so will usually warm the tire up enough the relieve the flat spot. I'm with everyone else, though, on changing yours after no more driving than down to the tire shop and preferably no faster than about 35 mph.
On one occasion when I was at Boeing, we left a fully loaded (800,000 pounds) 747 overnight for a test. Boy those tires really were "FLAT SPOTTED". It took about 60% take-off thrust to get that bird to move. They had rounded out by the time we'd taxied about two miles.
Frank Damp -Anacortes, WA,(DW- Eileen)
ex-pat Brits (1968) and now ex-RVers, as of 08 Dec 14.