Following the kind of tease routine that would put a Vegas stripper to shame, Mercedes will today finally unwrap its mile-munching Vision EQXX concept.

The German automaker set itself a target of creating the most efficient Benz yet, an EV capable of traveling 1000 km (621 miles) on a single charge, but rather than simply whack in a huge battery pack, which would add weight and cost, Mercedes is relying on a different, more intelligent strategy.

You can find out more about that strategy by tuning into the livestream event at 12.00 EST (18.00 CET) today, but from the glimpses we’ve seen so far we know it will feature an adjustable rear diffuser and won’t feature conventional door mirrors. And for anyone (us included) that was disappointed that the production EQS sedan looked rather unsexy compared with the EQS Vision concept that previewed it, you’ll be pleased to note that the EQXX promises a whole lot more sizzle.

View the EQS in profile and all you see is one boring unbroken curve stretching from the front bumper to the rear via the roof. But the EQXX displays a far more upright front screen, pronounced fender muscle, and a longer rear deck.

Related: ‘We Don’t Want It To Look Shit’: Mercedes Talks EQXX Concept Design In Latest Teaser

Mercedes claims that range and efficiency will define the future electric era, and says improving efficiency is key to starting a virtuous circle of battery size and weight reduction. There’s no word yet from Mercedes on whether we should expect the EQXX concept to make it to the street largely unchanged. But what we can be sure of is that almost all of the technology onboard will find its way onto showroom models, meaning that 1000-km range milestone (and a claimed single-digit kWh-per 100 km energy consumption at highway speeds) is no motor show fantasy.