BMW i8 Roadster (2018-2020) review

The BMW i8 Roadster adds open-top thrills to the Coupe's advanced technology, performance and efficiency

£127,105
Plug-in hybrid

Pros

  • Stunning performance
  • Efficiency and running costs
  • Supercar looks and style

Cons

  • Impractical body style
  • Pricier than the Coupe
  • Not involving enough
Car type Electric range Fuel economy CO2 emissions
Plug-in hybrid 23 miles 128mpg 50-51g/km

The BMW i8 Roadster followed the Coupe, a car that set a template for electrified sports cars, combining an efficient petrol engine with plug-in power for high performance. In 2018, BMW added an open-top variant to the line-up to give buyers more choice. The same great advanced powertrain was present to offer a mix of driving enjoyment and efficiency alongside its stunning looks and open-top thrills. Production was stopped in 2020, with no immediate plans for a replacement – this means that while you can buy from dealer stock, it is not possible to order a brand new i8 in either of its forms.

Although it took a few years to hit the market, the i8 Roadster still highlighted just how bold BMW was with the design and engineering of its plug-in hybrid performance car. That’s proven by the fact that this mid-engined carbon fibre roadster still has no plug-in rivals. All of the i8 Roadster's competition comes from non-hybrid competitors, such as the Porsche 911 Cabriolet, and there's still no sign of that changing even after i8 Roadster production stopped.

Like the Coupe, the i8 Roadster is defined by its driving experience. The combination of small petrol and electric motors is a technological tour de force and means it’s easy to drive – and easy to drive fast – thanks to the sophistication of that futuristic engine combination. In the middle of the clever carbon-fibre chassis, the i8 features a 228bhp 1.5-litre three-cylinder turbocharged petrol engine that drives the rear wheels through a six-speed automatic gearbox. This is joined by a 141bhp electric motor mounted at the front, so the Roadster also offers e-four-wheel drive capability. As a result, there’s 364bhp on tap, which is plenty given the i8 Roadster only weighs 60kg more than the Coupe, coming in at 1,595kg.

The i8 Roadster is a frugal machine that’ll at least be affordable to run, if not to buy. The claimed figures of up to 128mpg and CO2 emissions as low as 50g/km should be taken with a pinch of salt and are only realistic if you never run the car’s battery down. Charge it regularly and you’ll get closer to these numbers, cutting your fuel bills. The i8 in all its forms is Congestion Charge-exempt if you’ll be travelling into London, while a claimed electric range of up to 33 miles on a full charge (just one mile down on the Coupe) is a useful boost.

There are some negatives when it comes to practicality, though; you have to expect some usability drawbacks in a two-seat convertible such as this. Luggage space is extremely tight at just 88 litres. That’s not far off half as much as the Coupe.

You get a three-pin plug and fast charger capability with a Type 2 cable, while charge times range from roughly four and a half hours from a standard three-pin setup to less than two hours for an 80 per cent top-up from a home wallbox.

Performance, technology, economy and enjoyment are all present in the i8 Roadster – it's still 

and so is the extra element that buyers will be looking for here thanks to that electrically operated roof. It’s pretty much without a rival, even after BMW stopped making it. 

For a more detailed look at the BMW i8 Roadster, read on for the rest of our in-depth review.