I haven't tried it for long intervals but it seems more responsive to pedal input in B mode vs D and D always has arrows above 41 mph. where I can glide using B and have no arrows in the 50-70 MPH glide. Is that normal ?
Yes it is normal. B mode is for engine braking where the engine turns into an air pump to assist in braking. This is not meant to be used except when going down long downgrades and the HV battery reaches full charge. Once the HV battery is fully charged it disengages regen braking and reverts to engine braking to help prevent overheating of the friction brakes.
My BMW feels more responsive if I drive the freeway in 4th gear vs. 5th but it would be a silly thing to do in the long run. The Gen 3 cars have a button that you can push called Power. Power mode doesn't add any power, it just makes the accelerator more responsive. Try an experiment: Move your seat forward a notch. It might make it feel a little more responsive. Save B for that 5 mile long downgrade next time you're in the mountains.
