BMW 8 Series Convertible review

It’s a sports car, honest. Not our words, m’lud, the words of BMW. That’s what they insist the new 8 Series Convertible is. Despite the evidence to the contrary (the size, the weight, the back seats and so on) this is supposed to blur the lines between GT and sports car. More Porsche 911 rival than cruiser, according to the company that created it.

You’ve got to wonder if BMW is immediately getting off on the wrong foot there. The 8 Series is effectively a slightly more upmarket replacement for the old 6 Series. It too shares a platform with the 7 Series saloons. It’s a big, rather luxurious schlepping barge of a car, with its engine in the front. Insisting that it’s a sports car, because it’s fast and very stiff, might not do it any favours…

Proudly, BMW puffs outs its chest and declares that thanks to warm-welded pipe in the windscreen pillars and a torsion ring donut (mmm, donut) in the rear bulkhead, the new 8 Series drop-top is only two per cent less stiff than the coupe. Meanwhile, the chassis uses the same ‘carbon core’ blend of carbon fibre, steel and aluminium. It’s all very serious, very scientific, very… German. To prove it’s a sports car, you see?

Behind those widescreen nostril grilles, there’s a properly sporty engine. A new 4.4-litre, twin turbocharged V8, good for 523bhp. You can also have a straight-six diesel, but since we’ve not tested the 840d yet, for now we’ll concentrate on the M850i xDrive. Yep, it’s all-wheel drive, so you’ll never fluff a start. As a result, the M850i Convertible is good for 0-62mph in 3.7sec – exactly the same blistering time as the coupe, despite weighing 125kg more. So it’s certainly fast enough to be a sports car, and some.

The roof is a soft-top. After years of hefty, lumpy-looking folding hard-tops on Z4s and 4 Series Convertibles, the 8 Series (like the latest Z4 and the next drop-top 4, incidentally) opts for a canvas roof. Like the old 6 Series, in fact. It’s a swift mover, operable in 15 seconds at up to 31mph. BMW says its new hydraulically actuated mechanism saves three seconds of tedious folding time versus a fully electric system.

Prices start at £83,270 for the 840d, and leap to a whopping £107,045 for the M850i version, before options. Can the 8 Series Convertible justify such lofty pricing? We already had our doubts about the coupe, after all….

It’s difficult to put your finger on why the 8 Series doesn’t quite satisfy. You sit there in fabulous comfort, with great speed, much noise and all this tech at your fingertips, and yet it just doesn’t feel special, to drive or to sit in. It’s very much the top-of-the-range BMW. It feels like the best 4 Series you’ve ever sat in, not a true Mercedes S-Class or Aston alternative.

But is that the fault of the car, or just how BMW is pitching and pricing it? We judge the 8 harshly because it is precisely that: an apparent new 8 Series, not a new 6 Series. It’s supposed to conjure a sense of wellbeing greater than the sum of its parts, but as superbly engineered as the M850i’s soft-top version undoubtedly is, we’d still find different homes for our £100,000. We await the 840d version with interest – a fine swansong for diesel it may yet prove to be.