Audi has unveiled its Q6 e-tron offroad concept, and it sports a surprising feature: off-road-friendly portal gearboxes integrated into the wheel hub assemblies.

What Is A Portal Axle?

If you’re not familiar with portal axles, often simply referred to as portals, here’s the lowdown. A portal’s gearbox contains a series of gears housed in a casing that is mounted to the ends of an axle—or, in the case of an independent suspension setup, to the control arms. Portals lower a 4×4’s wheels relative to the axle or control arms, thereby raising the vehicle’s height. This shifts the lowest point of the axle upward, increasing ground clearance at the differential or control arms.

Another feature of portals is gear reduction. Simply put, the gears inside the portal housing provide gear reduction at the hubs. Among other benefits, this allows for the use of larger diameter tires without adding extra stress to drivetrain components.

Portal Axles Can Be Found Under Some Production And Custom 4x4s

Portals are rare, though they have been used in several production vehicles over the years, including the Hummer H1 and the Mercedes-Benz Unimog. Additionally, several rockcrawling and off-road racing vehicles have been fitted with portals. One example is Pat Gremillion’s legendary Jeep CJ, which is equipped with Hummer H1 portals. Recently, Ineos unveiled the Quartermaster pickup and Grenadier Station Wagon concepts, both fitted with portals.

Generally, there are two ways to fit your 4×4 with portals. One option is to do what Gremillion did and use secondhand parts. Alternatively, some companies offer new portal setups, such as 74Weld. At the time this story was written, the company offered applications for the Jeep Wrangler JL or Gladiator, the new Ford Bronco and Ranger Raptor, and a few Toyota models. Each application provides 1.22:1 gear reduction and 3.88 inches of lift, among other features. The company also offers its 2 Gear Crawler Portal and 4 Gear Race Portal.

Audi’s Portals Are Developed From Scratch

The Audi Q6 e-tron offroad concept is equipped with four portals developed from scratch. The company says these portals required modifications to the vehicle’s suspension links. It also notes that conventional portals typically increase torque at the wheels by approximately 20-30 percent, whereas Audi’s portals boost torque by 50 percent. The concept has a reduced top speed of 108 mph compared to the standard Q6, but the portals enable it to climb grades of up to 45 degrees. Additionally, the portals increase the combined torque at all wheels (10-second peak) to 9,883 pound-feet, a gain of 3,245 pound-feet.

6.3 Inches Of Lift

The Q6 e-tron offroad concept, based on the company’s PPE platform (Premium Platform Electric), features a 6.3-inch increased ride height compared to the standard Q6 e-tron and a 9.8-inch wider track. It is powered by two electric motors with a combined power output of 380 kW

After a test drive, Audi CEO Gernot Döllner said: “The Q6 e-tron offroad concept is a reinterpretation of quattro. The model shows the potential that our platform for all electric vehicles already has today. This vehicle can claim new ground. We look forward to seeing our customers’ reactions to this highly emotive car.”

Will We See More Portals From The OEs?

Whether you’re into electric vehicles or not, as an off-road fan, it’s worth applauding Audi for this portal-shod Q6 e-tron off-road concept. We’d like to see the company unveil a portal-equipped version of the ICE-powered A4 allroad.

Are we witnessing the beginning of an upward trend of OEs introducing portal-equipped, off-road-centric 4x4s? Time will tell.