"It is the torque of the town" sounds like "It is the talk of the town" meaning lots of people are talking about it. Torque is a measure of how much force it takes to cause an object to rotate. The more torque an engine produces, the greater its ability to perform work. The joke is referencing John Deere's most powerful tractor yet and replaced "talk" with "torque".
John Deere has just released its most powerful tractor yet . It is the torque of the town .