Infiniti issued a press release in conjunction with the recent Geneva Auto Show regarding Q50 MPG (and others stats). See here. Note that the news release was written for a European audience and discusses the European 4-cylinder models, but it also discusses the 6 cylinder and 6 cylinder hybrid. European MPG and U.S. MPG are not equivalent (you have to do a conversion), but here is my take:
6 Cylinder 3.5 liter Hybrid MPG: 37-38 MPG (U.S.) [45 MPG based on the British Imperial gallon, which is larger than the U.S. gallon]
I didn't see MPG estimates for the non-hybrid 6 cylinder.
That's better MPG than I expected for the hybrid (a material amount better than the M35h), although we'll have to wait for the "official" numbers for the U.S. Infiniti indicated in the press release that the Q50h will have faster acceleration than the M35h, and that other performance and efficiency improvements have been made to extend the MPG, including a longer electric-only range than the M35h.
6 Cylinder 3.5 liter Hybrid MPG: 37-38 MPG (U.S.) [45 MPG based on the British Imperial gallon, which is larger than the U.S. gallon]
I didn't see MPG estimates for the non-hybrid 6 cylinder.
That's better MPG than I expected for the hybrid (a material amount better than the M35h), although we'll have to wait for the "official" numbers for the U.S. Infiniti indicated in the press release that the Q50h will have faster acceleration than the M35h, and that other performance and efficiency improvements have been made to extend the MPG, including a longer electric-only range than the M35h.