Torque measured from a car engine, what does it tell me?
Torque is the twisting force the engine applies to the crankshaft. In SI units, the power of the engine is measured as the torque times the rotational speed. A horsepower equals 550 foot-pounds per second. Two engines with very different torque characteristics can have exactly the same horsepower since one horsepower can be generated by moving one pound 550 feet or moving 550 pounds one foot, as long as it is accomplished in one second. The high torque engine would be rotating proportionally more slowly than the low torque engine at the same power output, but twisting the crankshaft harder.
How much drag is on your car?
When you are driving along at a constant speed, the power produced in the engine is converted to force at the tires. The drag force acts in the opposite direction and is equal to the force that the engine creates at the tires. Since these forces are equal and opposite, the net force on the car is zero, so the car maintains its constant speed. If you take away the force produced by the engine (by putting the car in neutral, for instance) then the only force on the car is the drag. Since there is a net force on the car, the car will begin to decelerate.