In recent years, the debate between the constant-mesh cog which permanently drives the four wheels and the temporary one which, for its part, redirected power and torque to the wheels offering the best traction, had come to an end.
The first was, by far, considered the most efficient. It was barely recognized for being less economical at the pump as well as in maintenance. During this time, the device with temporary or reactive grip, it is according to, has progressed a lot. The reaction time of sensors and computers, once THE source of inequity between the various systems, is, for the vast majority of motorists, practically imperceptible today. And the addition (or improvement) of complementary crutches, such as the torque vector, has made it possible to reduce or even eliminate the difference between these two systems.
Moreover, several manufacturers are of this opinion. Lighter, less complex, the “new” four-wheel drive cogs consume less energy (difference of around 0.3 L / 100 km with an equivalent two-wheel drive model) and are less expensive to repair. . In short, they are more efficient and can no longer be qualified as reactive considering the power of the computers now used. They anticipate the switch to four-wheel drive before it becomes necessary. A feat made possible thanks to a real-time measurement of the level of grip and the inclusion of parameters such as the driver’s demand for torque (depressing the accelerator pedal), the steering of the steering wheel or the lateral acceleration. In addition, vehicles equipped with it generally start by default in four-wheel drive to ensure the best possible traction.
PHOTO PROVIDED BY FERRARI
Why keep it simple … With the Ferrari FF (our photo), the famous Italian brand has inaugurated a new four-wheel drive system that operates on the first four gears. Once the fifth is engaged, the FF becomes a propulsion again.
Another argument which militates in favor of a transitional system is visualized, on certain vehicles, by glancing at the animated infographic which makes it possible to follow the distribution of the forces between the two running gears. Many motorists will not fail to notice that the wheels only become fully driven on very rare occasions. Ferrari, to name but one, has long been aware of this with its GTC4Lusso model (born FF). This then inaugurated an original device which only drove the four wheels on the first four gears. From the passage of fifth gear, the FF drives only its rear wheels.
Food for thought
In truth, no matter which drive mode is stapled to your vehicle, it is safer than ever before thanks to the presence of certain devices such as stability control and traction control, not to mention the ” obligation to fit your vehicle with winter tires (which are constantly improving in performance). All these elements combine to make travel during the white season more pleasant.
That said, scientists, environmentalists and meteorologists all agree that Quebec winters are shorter and less snowy than in the past. Therefore, we can legitimately wonder about the relevance of a four-wheel drive.
The presence of all-wheel drive adds, it is true, an additional margin of safety. Approval too. For city dwellers, this driving aid represents a form of guarantee that the shovel will remain in the boot after a snow removal operation. For lovers of outdoor activities, the assurance of reaching winter sports resorts.
Today, the Quebec winter which rhymes more with rain than with snow is only one factor. A four-wheel drive, regardless of its operating principle (active or reactive), inevitably leads to an increase in fuel consumption and inevitably the emission of a greater quantity of greenhouse gases.
At the same time, the presence of a four-wheel drive system generally represents an additional outlay of some $ 2,000 if this drive mode appears in the options catalog, a sum that the consumer easily recovers when the vehicle is resold. Especially if the latter belongs to the category of light trucks, which currently forms nearly 80% of the Quebec market.
And the electric
SAGMEISTER PHOTO, PROVIDED BY AUDI
The 1980s constant-mesh mechanical all-wheel drive (competition UR-Quattro on the left) has been replaced by an on-demand electronic device that Audi intends to refine with its electric models (e-Tron GT on the right).
The same reasoning also applies to electric vehicles (EVs). Several of the latter also offer all-wheel drive by placing an electric motor on each axle. If, unlike a vehicle powered by an internal combustion engine, this has no impact on the environment, this driving aid does, however, have an impact on range, and therefore on the cost of use.