A DCT weighs 22 lbs more than a manual (15 lbs of that is greater dry engine weight), and is circulating nearly 30oz more oil than the manual. That 22 lbs is static weight in that it cannot shift around the chassis like a rider to enhance traction or lighten suspension at times.
While driven very conservatively over a standard U.S. EPA combined route the DCT might show better MPG, in real life the bike in DCT configuration is pushing more weight and churning more viscous fluid resistance than a manual — ridden identically in real life, I’d be surprised to see a DCT register mpg better than a manual.
Many folks see the DCT do better MPG in a “Sport” or “M” setting than “D”. Depending on how one rides, the early shifting in D can lug the engine and that will consume a bit more gas.
Atop that, there’s the traffic and congestion factor that will affect mileage.
Riding in a metropolitan area but with rural about 30 minutes out where the bike can open up and not have to move up-and-down over the entire RPM and torque spectrum, I’m averaging around 42 mpg. That’s pretty in line with most DCT’ers in The UK, Ireland, Continental Europe and The States. It’s a Honda, after all.