The roots of the current BMW 8 Series Convertible can be traced back to the 1990s when BMW mulled over the option of offering an E31-based convertible and produced a one-off model as part of the project.
Very little is known about this project as BMW tried to keep it behind closed doors as much as possible. What can be said for sure is that work on the E31 8 Series Convertible began in 1989 and continued towards the end of 1990.
The fate of the open-top 8 Series was concealed due to a mix of factors. The early 1990s saw Europe’s economies in quite an eventful geopolitical situations. Upon fear that the 8 Series Convertible would not be successful enough in terms of sales to justify its high development and production costs, the project never got the approval from the BMW top management for series production.
What is known for sure is that, if greenlighted, an E31 8 Series Convertible would have been a drop-dead gorgeous vehicle, with a mind-blowing silhouette and epic proportions. The Convertible managed to accentuate the sheer beauty and elegance of the 8 Series Coupe one step further.
Likely, the Convertible would have been offered with all the engine variants available for the 8 Series Coupe. The test bed for the project was the 850i version, powered by the 5.0-liter M70 V12 petrol engine, developing a peak output of 300 PS / 296 hp.
Imagine what a great collectors car would have been the 850CSi Convertible, for example. Powered by the heavily reworked S70 12-cylinder aggregate, the range-topping open-top 8 Series would have benefitted from a substantially enhanced powertrain and would have been capable of reaching a maximum output of 280 kW / 381 PS (375 hp).
I can only imagine how bloody sensational and exclusive an ALPINA B12 5.7 Convertible would have been. Packed with 416 PS (410 hp), a manual gearbox, add in a sunny day and some gentle wind in your hair and there you could have had the recipe for a ride in pure style.
During the project, the BMW 850i Convertible prototype has been subjected to both in-door testing in the aerodynamic wind tunnel and outdoor, on-street proofing, in camouflaged outfit like every future model.
Probably, as the rigid roof was replaced by a retractable soft-top, the E31 8 Series Convertible needed additional torsional rigidity measures to be taken, which meant extra weight was added to the car in the body reinforcement process.
In the end, it was concluded that, even though it could have been an attractive proposition in the segment and for the 8 Series lineup as well, the Convertible variant would have been a slow seller given the market context of those years.
Now, the only BMW 850i Cabrio (E31) ever produced (which is also road-ready) is exhibited and can be admired by visitors in the BMW Museum. The prototype is finished in what appears to be the Brilliant Red (code 308) exterior paintwork, an epic color that has basically become synonymous with the legendary E31 8 Series.
You might say that BMW didn’t literally have the guts to produce the E31 8 Series Convertible, but it is equally true it learns very much from past projects and experiences and knows how to capitalize its expertise.
That’s how the G14 8 Series Convertible was born. And the argument was to make the 8 Series revival an even more special one with the long-awaited version. While the modern 8 Series Convertible might not stay around for long afterwards, it certainly remains the most valuable tribute paid to the visionary, pioneering E31 BMW 850i Convertible.