In this realm of specialty engines that luxury cars make, it is definitely interesting to note the key factors that they are using to compete with Hybrids.
Granted, apart from the engine and the efficiency, there are a whole lot of what I call 'comfort factors' that set the luxury segment apart. But today's mid level and hybrids are not far behind to add these in. It is doing the other part that is tougher, i.e., adding a higher fuel efficient engine that can compete with hybrids, reduce carbon footprint by imposing strict rations to emissions, etc.
Volvo, VW and others are spending a lot of resources into developing these.
Complete article from Volvo's official site is: https://www.media.volvocars.com/global/enhanced/en-gb/Media/Preview.aspx?mediaid=31621