Acceleration test Mercedes W163 Ml 500

Hi guys so here is my ml500 , a lot of people says that ml500 accelerate from 0-62mph or 0-100kmh in 7.5 seconds. Mercedes says 7.5 . My benz has no problems to go below 7sec , it&around 6.54 . My Merc has 175000 miles on clock and runs like a dream.