“The potential for grid-connected vehicles to decimate our demand for liquid hydrocarbon fuels should be clear. Freed from the psychological barriers which hinder widespread market acceptance of pure battery electric vehicles, plug-in hybrids with an all-electric capability of just [30] kilometres would slash liquid fuel consumption, since such a high proportion of journeys undertaken are well within this range.”

"Plugged In: The End of the Oil Age” by WWF
(Dr. G. Kendall, 2008)

Overcoming the Problems of the Wankel Engine
The most obvious comparison is with the Wankel engine. The Libralato engine is predicted to overcome the principle problems of the Wankel engine:

The Wankel engine has a high surface to volume ratio at top-dead-centre (TDC) and a shallow and elongated combustion chamber – This ‘long flame path’ is principally responsible for the Wankel engine’s high fuel consumption and high level of unburned fuel (HC) emissions.
The Libralato engine’s second stage compression forces the intake air into a tightly contained combustion chamber. The force of combustion acts against an acute angle working surface area during the expansion phase. The surface area of the rotor face expands as it rotates, due to the sliding action of the rotors. This helps maximize the work to be extracted as the combustion pressure starts to drop and is predicted to be particularly well suited to lean burn combustion.
The Wankel engine suffered from unstable geometry of the rotor housing due to localized high temperature. It is known for having a ‘hot side’. This tends to deform the rotor housing and to reduce the effectiveness of the engine sealing.
The Libralato engine’s unique thermodynamic cycle involves the exit of exhaust gases under their own pressure and scavenge of residual exhaust gases by the first stage compression (~1.5 bar). This cycle helps to disperse and balance temperature gradients across the two sides of the engine.
The Wankel engine seals at the three apexes of the triangular rotor present a very small surface area and therefore tend to allow ‘blow by’ gas escaping.
The Libralato rotors have large sealing surfaces. Therefore the manufacturing tolerances should be much lower.