Skip advert
Advertisement

New BMW i8 Roadster 2018 review

The hi-tech BMW i8 plug-in hybrid loses its roof, but has it gained extra appeal over the Coupe?

Find your BMW i8
Compare deals from trusted partners on this car and previous models.
Or are you looking to sell your car?
Value my car
Fast, no-nonsense car selling
Value my car

As spectacular to look at as ever, the new-for-2018 BMW i8 still feels every bit the hi-tech sports car, too. Losing its roof has enhanced the experience; the open-top adds to the thrills, making it well worth the extra cash over the Coupe. There are alternatives for similar money that are more exciting to drive, but in lots of ways, the i8 makes them feel old-fashioned.

Advertisement - Article continues below

BMW has revised its i8 for 2018, introducing an all-new open-top version. The i8 Roadster sits alongside a revised Coupe, losing the latter’s solid roof and back seats, while gaining 60kg and an additional £12,000 on the price. But does that add up to a worthy trade?

The extra mass is a result of structural work to the carbon-fibre passenger cell. There are a few extra layers of carbon fibre around the windscreen and extra panels provide a stronger location for the Roadster’s rear suspension.

Best convertible cars

Elsewhere, the Roadster’s DSC system and adaptive dampers get unique tuning. Overall the i8 soft-top tips the scales at 1,595kg; hardly portly for a hybrid sports car with show-stopping gullwing doors.

The new roof is almost as spectacular as it delicately glides out of sight in a matter of seconds. It’s stored vertically where the back seats would be in the Coupe, and frees up an extra 92 litres of storage.

Skip advert
Advertisement
Skip advert
Advertisement - Article continues below

Used - available now

HS

2022 MG

HS

20,507 milesAutomaticPetrol1.5L

Cash £14,550
View HS
CLA

2016 Mercedes

CLA

85,087 milesManualPetrol1.6L

Cash £6,900
View CLA
Defender 110

2024 Land Rover

Defender 110

44,000 milesAutomaticDiesel3.0L

Cash £59,980
View Defender 110
Eclipse Cross

2019 Mitsubishi

Eclipse Cross

15,435 milesManualPetrol1.5L

Cash £12,450
View Eclipse Cross

As with the Coupe, the Roadster gains BMW’s latest electric technology. Battery capacity has increased, which bumps power up from 129bhp to 141bhp and battery-only range from 22 to 33 miles.

There was always a pleasing novelty to cruising around in silence in any i8, and that’s amplified (so to speak) without a roof. Call for more speed, and the petrol engine jumps in. It’s the same 1.5-litre three-cylinder as before, but with an added particulate filter to reduce exhaust emissions.

Advertisement - Article continues below

Performance might not be supercar-quick on paper, but in the real world it feels rapid. The instant shove of electric torque helps the i8 leap forward like a car half its weight, and the engine is more than willing to pull strongly to the red line, albeit without the thunderous drama of a Mercedes-AMG GT Roadster.

Nor can the chassis match that car for thrills. With the electric motor driving the front wheels and the petrol engine the rears, you have to be completely brutal with the throttle to even induce the slightest slip from the back end. Otherwise, the i8’s natural tendency is towards understeer. You’ll be hard-pressed to notice the Roadster’s extra weight compared with the Coupe, though.

Skip advert
Advertisement
Skip advert
Advertisement - Article continues below

• The best sports cars of 2018

However, the same can’t be said for refinement. While closed-top driving is perfectly fine, with the roof down, those buttresses generate a fair amount of wind noise at anything above 65mph. It’s a shame, because otherwise the i8 would be a fantastic long-distance cruiser.

But what about fuel returns? The 33-mile electric-only range is achievable in the real world, but you’ll need to make sure that the battery is well topped up for that to translate into hybrid-like mpg figures. Drive it hard, or simply treat it like any other performance car, and you’ll be unlikely to get much above 30mpg. Still good for a sports car, but some way short of the claimed 141.2mpg.

This test car comes with more than £10,000-worth of options, and we wouldn’t really bother with any of them. Half of that cash is taken up by laser lights – a feature that’s only really a benefit at full beam; another £2,750 pays for orange upholstery and £1,600 covers the carbon-fibre interior trim.

That material sits in an interior that is starting to look a little past its best. It’s not bad, but while the spectacular body still resembles a concept from 2030, the inside can’t match its theatre any more.

Skip advert
Advertisement
Chief reviewer

Alex joined Auto Express as staff writer in early 2018, helping out with news, drives, features, and the occasional sports report. His current role of Chief reviewer sees him head up our road test team, which gives readers the full lowdown on our comparison tests.

New & used car deals

Volkswagen Golf

Volkswagen Golf

RRP £24,640Avg. savings £2,419 off RRP*Used from £8,995
Omoda 5

Omoda 5

RRP £24,040Avg. savings £1,535 off RRP*Used from £19,290
Nissan Juke

Nissan Juke

RRP £19,805Avg. savings £4,614 off RRP*Used from £8,333
MG MG4

MG MG4

RRP £27,005Avg. savings £6,250 off RRP*Used from £9,790
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

New Jaecoo 9 flagship SUV coming to the UK to target the Range Rover
Chery Fullwin T11 - front

New Jaecoo 9 flagship SUV coming to the UK to target the Range Rover

The new six-seat Jaecoo 9 SUV will be based on the Chery Fulwin T11, and it's coming to the UK
News
28 May 2026
Car Deal of the Day: Skoda Superb Estate for just 18p more a month than smaller Octavia
Skoda Superb Estate - front full width image

Car Deal of the Day: Skoda Superb Estate for just 18p more a month than smaller Octavia

The Skoda Superb is one of the finest family cars money can buy. It’s our Deal of the Day for 28 May.
News
28 May 2026
Peugeot goes price-cut crazy with huge discounts across the range
Peugeot range

Peugeot goes price-cut crazy with huge discounts across the range

From the 208 to the 5008, Peugeot has rethought its pricing to make its range “more accessible than ever”
News
28 May 2026