No, hes talking about regular foot Infantry. What he stated is a fact. The military unit record for largest sustained daily gains in km/day belongs to this day to Mongol Horse Archers who averaged something like 25/km a day which is pretty impressive. While Tank units tactically were faster than other units, when you averaged it all out, they faired about the same as Infantry in ground gained. The way your imagining it, tanks would have to be able to go full throttle without any contact with the enemy. Thats not how battle went (or goes for that matter). When tanks get into contact or EXPECT to be in contact, they slow down dramatically for security. Tanks blowing through will suffer horrendous casualties to AT Infantry in spider holes, land mines, and well placed AT guns. Now, if the tanks were able to get through without contact, sure they might make some substantial gains. But at the end of the day, when you average it out, it works out the same as Infantry.
Unless you consider the historical mechanized progression where the only infantry that moved as fast as the tanks, even in averages, were those with motorized transportation. You see, you're assuming tanks in constant contact but the virtue of the tank is that it does not need to be in constant contact to achieve its goal. This was the entire point (proven in battle) of the theories put forth by Heinz Guerdadin and Erich Von Manstein. The only times where this principle didn't play out was against other tanks or in severely bad logistical situations. In tactical principle, the tank is the cavalry: unable to hold territory or successfully assault infantry (the Mongols were a dramatic exception to this rule because of Mongol innovations in command and control) but capable of outpacing infantry, engaging and disengaging at its leisure and smashing the logistical organization of the opposition to hell.