Like the classic 13B engine that the current Renesis is still based on, the new 16X would use two rotors, though enlarged to 800cc each for a total of 1.6 liters. Despite the increase in displacement, Mazda hopes to increase fuel economy and reduce emissions by 20 percent.
Other efficiency improvements are planned as well, including a dual-clutch transmission and a significant weight savings over the current RX-8, which isn't exactly a porker as it is. Supposedly, the new rotary would be available in both a two-door, two-seat RX-7 and a larger, four-seat RX-9 variants.
[Source: Inside Line]