Mercedes S-Class plug-in hybrid review

A massive 62-mile electric range and a sumptuous, high-tech interior move the new 2021 Mercedes S 580 e plug-in hybrid to the front of its class

Mercedes S 580 e plug-in hybrid
£100,000
Plug-in hybrid

Pros

  • Huge electric range
  • Stunning interior
  • Flat boot floor

Cons

  • No all-wheel-drive
  • Only long-wheelbase
  • Not available until 2021
Car type Electric range Fuel economy CO2 emissions
Plug-in hybrid 62 miles 177-217mpg 29-37g/km

The Mercedes S-Class has dominated the luxury saloon class for decades, and every generation has introduced new technology that has rivals struggling to catch up, and which eventually finds its way onto more affordable cars.

When it comes to the all-new 2021 S-Class, that new technology includes an optional Drive Pilot cruise control system that allows you to take your hands off the wheel long enough to watch a film in slow-moving traffic, as well as this plug-in hybrid model with a battery twice as big as the outgoing car’s – and double the electric range of its BMW 7 Series and Audi A8 opposition.

Called the S 580 e, it follows the same recipe laid down by last year’s S 560 e, combining a 3.0-litre six-cylinder petrol engine with an electric motor. The petrol engine makes the same 362bhp it did previously, but now it’s supplemented by 148bhp of electric power instead of 121bhp. Working together, they deliver an impressive 510bhp, up from 470bhp for the S 560 e. That helps the new car demolish the 0-62mph sprint in an estimated 4.5 seconds, making the S 580 e the fastest, most powerful S-Class available in the UK until the inevitable AMG version appears.

Neither the Audi A8 60 TFSI e or BMW 745e can match the S 580 e's firepower, but more importantly, they’re even further away when it comes to fuel economy and electric driving range. Both will do around 26 miles on electric power with their sub-15kWh batteries, as would the old S 560 e. But because Mercedes has increased the size of the battery pack under the boot floor from 13.5 to 28kWh, the S 580 e will run for 62 miles before the petrol engines is forced to cut in.

That’s an official Mercedes figure, but we drove for 40 miles on a mix of German roads, reaching 80mph in places, and still had 20 miles remaining on the range display. And that extra-large battery has a significant impact on running costs: official economy improves from 108-113mpg to 177-217mpg, and the 29-37g/km CO2 rating is the lowest among hybrid luxury cars. When the petrol engine does join in, either because you’ve depleted the battery, or because you’re asking for a big kick of acceleration, you barely notice the switch, so smooth is the integration of the two engines, and so well insulated is the stunning interior.

Featuring a 3D instrument panel and augmented reality head-up-display that overlays navigation arrows onto your view through the windscreen, the cabin is dominated by a huge central touchscreen running the latest version of Mercedes’ MBUX infotainment software. Almost all of the car’s function have migrated to the 12.8-inch screen, but fortunately a call of ‘Hey, Mercedes!’ followed by a command is usually understood. And importantly, since the most important person in this car will often be in the back, the voice commands are picked up wherever you’re sitting.

Unlike the entry-level £78,705 S350d diesel, the circa-£100,000 S 580 e will only be available in 110mm-longer long-wheelbase form, meaning plenty of legroom for those rear passengers. And this time there’s no awkward step in the boot, which at 520 litres is easily the best in the class. But at 5,289mm between bumpers, the stretched S-Class is a big car: we’d definitely recommend the optional four-wheel steering system, which transforms the manoeuvrability, giving it the same turning circle as an A-class hatchback.

Air suspension is standard, coping well with all but the most severe urban bumps and potholes and giving the S a better ride than its rivals. It steers accurately, too, but drive quickly and you’re reminded both of extra weight of the battery pack versus a non-hybrid S-Class and that this 580 e doesn’t benefit from Mercedes' 4MATIC all-wheel-drive system.

Most S-Class buyers, however, won’t be driving quickly, and although the S 580 e is expensive, it’s the standout car both in the range and in the class – at least until its sexier, all-electric EQS sister arrives. Although it's likely to cost up to £10,000 more than its major rivals, it outshines them with stronger performance and an excellent 62-mile electric range that you can enjoy in the quietest, most elegant cabin this side of a Rolls-Royce.