The new platform and soft top should contribute to a major reduction in weight.
A new batch of spy photos provides a great look at the upcoming BMW 4 Series Convertible while testing near the automaker's Munich headquarters. The droptop continues to wear lots of camouflage, but the pictures provide a good overview of the vehicle's shape.
The overall styling looks a lot like the upcoming 3 Series sedan, which is only a few weeks from debuting at the Paris Motor Show. Test mules so far seem to show the 4 Series with a slightly rounder nose than its four-door counterpart, but this could easily be a visual distortion from the camouflage.
The new 4 Series Convertible switches to a soft top instead of the current model's folding metal roof. The fabric panel should be quite a bit lighter and would lower the vehicle's center of gravity, which might make the machine more tossable on curvy roads.
Like the 3 Series, the new 4 Series moves to BMW's CLAR platform. On other models, the updated underpinnings let the vehicles shed weight, and it's safe to expect a similar weight loss for these new models, too.
The pair should also share the same powertrains. There should be a wide variety of powerplants available, but the only one that BMW confirms so far is the introduction of its most powerful four-cylinder ever that makes 252 horsepower (187 kilowatts). A plug-in hybrid would be part of the range eventually.
Look for the new 4 Series in both the coupe and droptop varieties to debut in 2019, but they might not be on sale until 2020. This timing means there should be plenty more spy shots and videos of the development until the unveiling.