WATCH: Rivian R1T driven hard in the desert

Pure-electric start-up Rivian has released a new video of the upcoming Rivian R1T pick-up being given a thorough shakedown by its engineers in the build-up to its 2021 launch.

The short vid, posted on Rivian's official social media channels, shows what is thought to be a late-stage development mule undergoing evaluation at a secret testing facility in Arizona.

Including footage of the battery-powered ute tackling the harsh desert terrain, driving flat-out on unsealed roads and even drifting on a racetrack, the new vid gives us an idea of what Rivian's first model is being subjected to in the pursuit of "exploring the limits" of the R1T.

It's thought testing in the punishing terrain and scorching temperatures is vital not only to see if the all-new architecture and suspension systems are up to scratch but to also ensure the battery keeps cool and remains capable of delivering peak power whatever the conditions.

Slow rock-crawling, meanwhile, tests whether or not the underbody's bash plates and armour are tough enough to prevent any sharp stones from piercing the fragile, and potentially explosive, lithium-ion battery pack.

Inside, we even get a glimpse of the production car's full digital instrument panel, hinting at a tech-laden cabin that should push new boundaries in the working-class market segment.

It was originally planned for a launch later this year, but Rivian now says the R1T will reach US customers in 2021, following the COVID-19-related shutdown at its Michigan-based former Mitsubishi factory.

The initial plan is to sell the R1T with three battery options offering 105kWh 135kWh and 180kWh.

Despite measuring 5.5-metres long and weighing a hefty 2.6 tonnes, the dual-cab 4x4 pick-up is said to be capable of hitting 100km/h in around three seconds and deliver a range of between 370km and 650km.

Perhaps more incredibly, thanks to its four 147kW electric motors, the R1T will offer 14,000Nm of torque.

Each truck comes with a more modest 11kW on-board charger, but Rivian says it is working on a new 160kW fast-charging station.

The Rivian R1T features adjustable air suspension that can rise ground clearance to as much as 360mm to help it wade up to a metre of water. The only potential fly in the ointment is the battery-powered ute’s payload is limited to just 800kg.

Making up for that though is Rivian’s claim the R1T will be capable of towing up to 5000kg.

As well as extolling its off-roading prowess, the US truck-maker claims that when it goes on sale the R1T will come with Level 3 autonomous driving aids (hands-off, feet-off and eyes-off) but has not confirmed whether it will be active from launch.

US pricing for the Rivian R1T is expected to open at around $US69,000 ($A110,000) and the electric ute will be followed by the Rivian R1S seven-seat SUV.

Both electric models will be built in right-hand drive but it’s not yet known when either vehicle will arrive in Australia.