Holden's 3.6-litre engine gets new valves to enable it to run on liquid petroleum gas.
Holden will introduce a dual-fuel model to its large-car Commodore range, using a modified version of the carmaker's 3.6-litre engine.
The Alloytec V6 unit gets new valves and hardened valve seats to enable it to run on the liquid petroleum gas cycle.
Holden says the LPG is injected directly into
the air intake runner, eliminating excess gas circulating through the air intake system.
The system gains further efficiencies by mimicking the petrol injection sequence, which allowed engineers to achieve power and torque figures close to theoretical LPG maximum efficiencies, it says.
Like the petrol-only Executive, power is 175kW (235bhp) at 6000rpm with 320Nm of torque at 2800rpm.
Holden says the the dual-fuel Executive meets Euro 2 emission standards. LPG fuel economy is 14.4 litres/100km (sedan) and 14.8 litres/100km (wagon). Petrol fuel economy figures remain unchanged at 11.1 litres/100km (sedan) and 11.3 litres/100km (wagon).
Holden says significant development work was undertaken to ensure a seamless transition from petrol to LPG while driving, with no discernible power difference.
The LPG system uses petrol on start-up, then automatically transfers to LPG, if selected, once the engine has warmed up.
Another advantage of the gas-powered Commodore is the fuel filling point - the gas outlet is located above the petrol cap behind the fuel filler door.
The dual-fuel system requires an LPG-system service only every 15,000kms.
The dual-fuel VZ Commodore Executive is priced at $49,570 for the sedan and $52,350 for the wagon.
