The other reason that 0-100kph(62.5mph) often takes longer than 0-60mph is because of an extra shift. Because of the 0-60mph test, most cars are being geared so that the car can reach 60mph before the 2-3 shift.
However, reaching 100kph(62.5mph) often requires a 2-3 shift, and adds a few tenths to the time.
