MTB Tire performance
I'm not sure if I follow you exactly, but I ride road and dirt. More to it, I ride my mountain bike on the road on the way to the dirt. Here's my $0.02.

The tires on my mountain bike are inflated to about 32-35 PSI (2.2-2.4 bars), and they have a lot of rolling resistance on asphalt. The sensation of riding on them is entirely different than my road bike tires, which are typically inflated to 105-110 psi (7.2-7.6 bars). The mountain bike tires feel like they are flat, even when I know they are not. I find myself looking down at them, wondering if they are still holding air. In my defense, on the mountain bike, I use tubes filled with a sealant, so it is possible for a puncture-- a thorn, maybe, or a piece of wire from a car tire-- to cause a slow leak. When you pull the thorn or wire out, there is a little puff of air that escapes, but the sealant usually closes the leak almost immediately. But it is not foolproof, and I can't shake the feeling the tires feel flat, even if I just aired them up before riding.