Audi is exploring ways to install gasoline engines in electric vehicles without redesigning their structures, while also developing a system intended to improve the efficiency of extended-range electric vehicles (EREVs). Two patents outline concepts for fitting compact engines into EV platforms and managing gasoline and electric power based on driving conditions, route requirements and energy costs.
Audi’s Patent Shows How a Gas Engine Could Fit Into an EV
The first patent describes a method for installing a gasoline engine in a vehicle originally designed as a battery-electric vehicle. Instead of mounting the engine to a subframe and strut towers in the conventional manner, the proposed design would suspend it from a strut brace.
This setup could allow engineers to install an engine in an empty compartment designed for an electric vehicle, even if the original structure was never intended to accommodate a combustion engine.
The proposed gasoline engine would be relatively small, potentially featuring one or two cylinders, and positioned at an angle inside the engine bay. This arrangement would help lower the vehicle’s center of gravity while reducing the space occupied by the engine.
Rather than connecting the engine to a conventional transmission, the design would link it to the electric motor. The motor could then operate as a generator, allowing the gasoline engine to produce electricity to charge the battery.
Although the concept is unconventional, mechanics already use a bar spanning the strut mounts to support an engine during certain service procedures.
Audi Wants to Make Extended-Range EVs More Efficient
The second patent focuses on improving how an extended-range electric vehicle uses its available energy. Audi’s concept identifies the gasoline engine’s efficiency as a key consideration, noting that these engines convert approximately 25% to 40% of fuel energy into useful output.
Rather than running the engine without considering operating conditions, the proposed system would use it strategically. In certain situations, the gasoline engine could generate heat for the passenger cabin or precondition the battery.
Plug-in hybrid electric vehicles already use gasoline engines to generate heat because an engine can be more effective at producing it than a heat pump or an electric grid heater. The proposed approach would not work when the battery is fully charged, but it could be used at other times.
Navigation Could Balance Gasoline and Electric Power
Audi also proposes using trip planning to help reduce overall driving costs by managing the balance between gasoline and electricity. If a driver enters a destination beyond the vehicle’s available battery range, the navigation system could compare the cost of fast charging with the cost of fuel.
Based on that comparison, the system would optimize the use of gasoline or electricity during the journey according to which option is less expensive.
Weather conditions could also influence the vehicle’s energy strategy. If a route includes cold weather, the system could plan charging stops and gasoline use accordingly.
Additional factors could include mountain grades, maximum road speeds and expected traffic. The vehicle would calculate these conditions alongside energy costs to determine how best to manage its available power sources throughout the trip.
The two patents outline a potential approach to extended-range electric vehicles, combining a compact gasoline engine installation with a system designed to manage energy use according to route conditions, weather and operating costs.
