Ferrari has made a patent application for a clever four-wheel drive hybrid system, which could be fitted to both its front- and rear-engined models.
The company’s idea is to reduce the complexity of conventional hybrid systems by separating the roles of the engine and the electric motor.
Under the Ferrari proposals, the electric motor will independently operate one pair of wheels and the engine the other pair.
Ferrari has submitted six different layouts for the patent. In all of them the engine drives a motor/generator, which in turn drives one pair of wheels via electricity provided by an on-board battery.
However, some of the proposals see the wheels driven by a conventional differential and axles and in the others, small, in-wheel, electric motors will be used to drive the wheels.
The patent application says that the hybrid system is designed to improve handling rather than reducing fuel consumption.
“The aim of the present invention is to provide a four-wheel - drive vehicle with hybrid propulsion…and being at the same time easy and inexpensive to produce.”
Ferrari says that this kind of ‘part time’ 4x4 system is not only less complex, but lighter and less troubled by frictional losses. It also means all-out performance is not permanently blunted because the engine does not have to drive all four wheels all of the time.
According to application, “The four-wheel drive that can be engaged enables the driver of the automobile to decide whether to use the rear drive or the four-wheel drive; in this way, the driver can use the rear drive in optimal conditions of adherence and can use the four- wheel drive in poor conditions of adherence”.
Even though Ferrari has not mentioned the ecological aspects of adopting hybrid drive, the set-up would almost certainly allow engineers to incorporate a stop-start system for the engine, reducing fuel consumption.
The electric drivetrain should also allow the car to pull away from a standing start using only electric power. Starting the engine only when the car is travelling at 10mph+, will also reduce the level of pollutants produced by the engine.
Ferrari engineers could incorporate a ‘city’ mode in future hybrid models, which allows electric-only starting and a ‘performance’ mode for out-of-town performance driving.
Onboard rain and temperature sensors could also be used to automatically activate four-wheel drive running in bad weather. Information from the car’s chassis electronics could also bring the 4x4 system into play when the driver is pushing the car hard.