Audi wants to put gas engines in its electric cars. If that seems like a step backward, you’re not alone. But the idea here isn’t to gasify EVs. Not entirely, anyway. CarBuzz has just found a patent that describes this interesting idea.
And then we found another patent that could make extended-range EVs (EREV) even more efficient than a straight battery-electric car.
Engine Swap Without Redesigning The Car
Audi EREV Engine PatentAudi
The first patent describes a method to put an EREV’s gas engine into a vehicle designed as an EV. That doesn’t sound like something worthy of a patent, but Audi likes to do things differently and, naturally, this idea is wild.
Instead of mounting the engine to a subframe and strut towers in a typical fashion, Audi wants to hang the engine from a strut brace. That would let engineers install the engine into an empty bay made for an EV, one that wasn’t designed to ever hold an engine in the first place.
The small gas engine, likely just one or two cylinders, would be laid back in the bay. That works to lower the center of gravity and helps the engine take up less space. The engine would also be attached to the electric motor instead of a transmission, in order to use the motor as a generator and charge the battery. It sounds wild, but mechanics will hang an engine from a bar across the strut mounts for service quite often already.
Could Audi Make A Better EREV Algorithm?
With a plan to “hang” an engine in an EV established, how would Audi make it more efficient? By reimagining how the EREV engine is used. Audi points out that the gas engine in an EREV is still inefficient by design, pointing to 25-40% efficiency from the fuel. Because the gas engine isn’t efficient, it only makes sense to use the range extender in certain situations.
The German automaker wants to raise the efficiency of the system, and it starts by using the EREV engine in certain situations to generate heat for passengers in the cabin, or to pre-condition the battery. PHEVs already do this, because the inefficient gas engine is still more effective at generating heat than a heat pump or electric grid heater. It wouldn’t work with a full charge, but it would work the rest of the time.
Audi also wants to lower your total costs by cleverly balancing gas and electric power by managing your trip. If you set a destination further away than a full charge will take you, the navigation system will look at the cost of fast charging as well as the cost of fuel. Depending on which is cheaper, that mode of propulsion will be optimized for the drive.
It could also look at the weather to determine when to use gas or electric. If you’re going to hit cold weather along your route, it could plan charge stops and gas use accordingly. Different route factors, like mountain grades, maximum road speeds, and expected traffic, could all be part of the equation that the car calculates.
CarBuzz Insight – Why This Matters:
All-new 2025 Audi SQ5 hero shotAudi
Making it easier to drop a gas engine into an EV could help salvage some of Audi’s EV program investments. This gives buyers in EV-hostile markets like the US something that delivers low consumption, high flexibility, and low development and purchase costs.
The new control system, though, really changes the EREV game. Audi’s engineers want to more fully integrate the EREV system instead of simply carrying the extra weight and fuel around most of the time. If that can really improve overall efficiency, it’s a big plus for Audi, customers, and the environment.
Patent filings do not guarantee the use of such technology in future vehicles and are often used exclusively as a means of protecting intellectual property. Such a filing cannot be construed as confirmation of production intent.
Source: DPMA, United States Patent & Trademark Office
