BMW i8 Roadster (2018-2020)

Models Covered

2dr Coupe


The BMW i8 aimed to re-define the art of sports car design – both technologically and aesthetically in this Roadster guise. It may not be the ultimate contender of its kind from the 2018-2020 period to drive but it could well be the ultimate model of this type to own. This is, after all, a plug-in petrol/electric hybrid super sports car that runs silently on its battery in the morning commute, yet can transform itself into a high performance GT when you’re in the mood. It also looks sensational, feels special and will slash your running costs to the bone.

The History

You’re looking at a model that claimed to represent the future of open-topped sports cars. One that was light, strong, very fast and more than able to justify its position on the planet. Welcome to BMW’s revolutionary i8 Roadster, sold briefly between 2018 and 2020.

You might be familiar with the i8 Coupe, the model that democratised sophisticated hybrid technology in the high performance super sports car segment. Until this revolutionary model arrived in mid-2014, plug-in petrol/electric sportscar motoring required the billionaires’ budget needed for ownership of hypercars like the Porsche 918 Spyder, the La Ferrari and the mighty McLaren P1. At a stroke, this BMW changed all of that, delivering an equally sophisticated taste of the future, but doing so for realistic Porsche 911 money.

Originally, BMW designed the i8 as a Coupe, but showed a Spyder concept version at the Beijing Motorshow in 2012 to see if there would be enough customer interest in an open-topped version. There was and when the design team removed the roof of a fixed-top model and found the carbon fibre chassis easily stiff enough to support a convertible format, the Munich maker gave the green light for production. Following which the i8 Roadster was launched in the Spring of 2018.

It arrived on the market at the same time as the i8 Coupe was receiving a significant update, most notably to its rather unique powertrain. That’s based around the use of two gearboxes, three electric motors and a sophisticated three cylinder turbo petrol engine, this boosted by a 200kg bank of hi-tech lithium-ion batteries and transmitting torque to the tarmac via a four wheel drive system. As part of the mid-term improvements, BMW has added 12hp to the engine output, while upgrading the cell capacity of the lithium-ion battery to 34Ah and increasing its energy capacity to 11.6kWh, in the process raising this car’s potential pure electric driving range by 10 miles to 33 miles.

It was all enough to further distance this i8 from its conventional super sports car rivals. And in this Roadster form, buyers got an extra element of exotic desirability. But would you really pay Porsche 911 money for a three cylinder 1.5-litre Plug-in hybrid convertible? We think you might if you’re in the market and have half a care for the environment. The i8 in both Coupe and Roadster forms sold until 2020 – and wasn’t replaced.

What You Get

Even standing still, there’s a sense of theatre about this i8, with a riot of complex surface treatments, contrasting colours, sharp creases and scalloped sills. For this Roadster version, BMW revised this car’s distinctive dihedral doors to integrate frameless windows and better fit with the new roof arrangement. It’s a fabric top that activates in 15 seconds at speeds of up to 31mph, folds in a Z-shape and stows vertically in the space where tiny back seats would be in the Coupe model, nestling between the rear bulkhead and the mid-rear-mounted combustion engine. As ever in an i8, the packaging is necessarily intricate, given the need to accommodate two gearboxes, three electric motors, a three cylinder turbo petrol engine, a 200kg bank of hi-tech lithium-ion batteries and all the associated technology of 4WD.

In the cabin, you’ll find the styling as futuristic as it was outside, the curved, layered dash made up of overlapping three-dimensional segments and complemented by contrasting colours. Cocooned yet surprisingly roomy, the driver-focused cockpit envelopes you with slender blue-stitched leather sports seats, re-designed here as part of a package of mid-term i8 updates that also included the standard inclusion of these carbon fibre trimming panels and the addition of touchscreen functionality for the 8.8-inch iDrive infotainment monitor positioned at the top of the dash.

What To Look For

Obviously check the condition and working of the electrically-powered top, but you’re unlikely to encounter any issues. Otherwise, it’s just as with any other i8 Coupe – and probably better because by the time of this Roadster variant’s introduction, BMW had ironed out most of the major issues with this car. Our owner survey did reveal one i8 owner with serious issues relating to drivetrain and overheating, probably related to a problem with the central controller. Basically, if you have any sort of issue, it’s likely to be expensive, so inspect carefully and obviously, insist on a fully stamped-up service history.

On The Road

The i8 Roadster claimed to be something quite new: a super sports car promising the thrill of high performance open-topped motoring, but with near silent aural accompaniment from its electrically-assisted powertrain. That’s the case when you drive this car in one of its ‘eDrive’ modes anyway, which work at speeds of up to 75mph and deliver top-down progress that amplifies the sights, sounds and smells of the world around you. As in the Coupe version of this model, the electric motor’s sited up-front, drawing charge from a high voltage lithium-ion battery that powers the front wheels through a dedicated two-speed auto gearbox. This set-up works in concert with a tiny MINI-sourced 1.5-litre three cylinder petrol powerplant sited in a mid-engined format behind the back seats, simultaneously driving the rear wheels via another auto gearbox, this a more conventional one with 6-speeds. On the move, there’s 4WD traction and some serious pep, 62mph from rest achievable in just 4.6s on the way to a maximum speed that must be reined in at 155mph.


Like its coupe counterpart, this i8 Roadster offers a fundamentally different interpretation of what a super sports car can be. Nothing else we can think of in this segment from this period is so striking, surprising and sensational, yet so ultimately sensible in what it sets out to offer. It’s a landmark car: nothing more, nothing less. And an incredible achievement.