Honda civic hybrid

There's no maximum vehicle speed that limits the use of the electric motor. Since the Electric motor is inline with the crankshaft and the engine's maximum RPM is well below 10000 RPM, the HCH-II stator/motor is not bound by any practical operational constraints as it is in other hybrids (i.e: Prius).

However, triggering "EV only" propulsion at higher speeds is an exercise in futility since the motor cannot produce enough power with its 15KWh rating to overcome the aero drag forces. At best you'll get a longer coast - at worst you'll get a depleted pack. :)

Cheers;

MSantos

The Civic Hybrid is a "power assist" hybrid in that the gas engine is always the primary source of motive power. The only thing the electric motor is allowed to do is assist the gas engine or take over the propulsion duties for brief periods of time and under very unique conditions.

The minimal speed at which the electric motor is allowed to power the engine by itself is roughly 20km/h (~12MPH). Look for an RPM of 1000-1100 as an indicator of EV only propulsion. Any RPM above this will likely come from the activation of the gas engine.

Some people claim to have had their HCH-II on EV-only operation under 20 km/h but that might have happened as a result of glide coast or some other circumstantial anomaly.

Cheers;

MSantos

Sorry.
I don't quite understand what you mean by "gradeability". Could you re-phrase your question?

MSantos

Based on tests cycles that I've seen so far (independent and government) it can vary a fair amount since SoC plays a fundamental role in that type of performance test.
But in the larger context, I frankly don't know which to believe in.
As far as I can tell, Honda does not supply such information either so instead of just guessing I'll just say I don't know. Sorry. :(

Cheers;

MSantos