For 40 years, Audi has been extolling the benefits of permanent all-wheel-drive with its quattro system.
A novelty in cars when it first came out in the now-iconic Quattro sport coupe, it made its point in motorsport throughout the 1980s, notably in World Rally Championship events and in Trans-Am racing.
The power distribution and traction advantages of all-wheel-drive have caused other automakers to adopt and adapt the technology to their own products, from high-end sports cars and luxury cars to everyday family sedans and compact cars.
And while Audi continues to develop and fine-tune the mechanical versions of quattro throughout its lineup of cars and crossovers, its leap into the electric vehicle market with its e-tron crossover has created a new type of quattro system, one that removes the mechanical element.
“For us, the electric quattro is the perfect combination of powerful performance and high efficiency,” says Michael Wein, project leader, all-wheel-drive control systems, at Audi. “We combine the efficiency advantages of a driven axle with the traction and dynamic performance of an all-wheel-drive system.”
In the current e-tron model range, only the rear wheels propel the crossover under optimal traction conditions, while the motor for the front-wheel-drive concurrently runs without being energized. Since the motor is an asynchronous type, there are no inherent electrical drag losses, so, says Audi, the drive layout consumes a low amount of energy. The front axle is activated only as needed, such as when encountering slippery roads or when under heavy acceleration.
In the e-tron, one electric motor each drives the front and rear axle. Audi, however, has just debuted the new e-tron S and e-tron S Sportback in Europe. These much higher-performance versions – 496 horsepower and 718 pound-feet of torque! – use one motor on the front axle and two on the rear. With electric torque vectoring, the e-tron S provides quattro drive on the rear axle with greater effectiveness.
The key advantage, says Audi? Without a mechanical connection between the two electric motors on the rear axle, the functions of a controlled transverse differential lock and thus the functions of a sport differential have been achieved within a single system by means of software-based activation.
In addition to the electric all-wheel-drive, the two e-tron S models are equipped with electric torque vectoring: Each of the rear electric motors sends torque directly to the respective wheel via a single-speed transmission. Again, there is nomore mechanical differential.
Considering the e-tron S and Sportback S crush the scales at almost 2,700 kilograms, Audi’s claim they will accelerate to 100 kilometres an hour in just 4.5 seconds is impressive. Unfortunately, for fans of electric vehicles – and performance – Audi Canada will not confirm any plans at this time to bring the e-tron S in either body style into the country.