|GM Holden Commodore|
GM Holden (Australia) is launching new dual-fuel versions of its large sedan and wagon, the Commodore, featuring a newly-developed version of its 3.6-liter Alloytec V6 (one of GM’s global engines).
The engine is modified to run on gasoline and LPG, using a new injection system, new valves and hardened valve seats designed for LPG operating conditions.
The LPG system uses gasoline on start up, then automatically transfers to LPG, if selected, once the engine has warmed up.
Based on the Executive model, the LPG-powered Commodore uses a sequential vapor gas injection (SVGI) which injects gas directly into the air intake runner, eliminating excess gas circulating through the air intake system.
The SVGI system gains further efficiencies by mimicking the gasoline injection sequence, allowing engineers to achieve power and torque figures close to theoretical LPG maximum efficiencies.
(SVGI systems are used in LPG conversions and dual-fuel systems from a variety of vendors.)
GM Holden engineers strove to provide a seamless transition from petrol to LPG while driving, with no discernible power difference. Like the gasoline-only model, the engine fueled by LPG power delivers 175 kW (235 hp) with 320 Nm (236 lb-ft) of torque.
Gasoline fuel economy figures remain unchanged at 11.1 liters/100km (21.2 mpg US) (sedan) and 11.3 liters/100km (20.8 mpg US)(wagon). LPG fuel economy is 14.4 liters/100km (16.3 mpg US) (sedan) and 14.8 liters/100km (15.9 mpg US)(wagon).
With the increase in oil prices, there is a resurgence in interest in LPG as a fuel.
ABC Rural in Australia reports that demand for LPG conversions in the country have increase about 20% on average, with some areas higher than that.
In New Zealand, One News reports that inquiries about converting to LPG have quadrupled in recent months, reminiscent of the last oil crisis 25 years ago.