HOLDEN Special Vehicles (HSV) expects only five per cent of its buyers to opt for its Australian-first Liquid Propane Injection (LPI) system, but most of those will be new to the brand, drawn by the environmental benefits and cost saving of the new technology developed in partnership with Perth-based Orbital Engineering.
That would equate to almost 200 sales of HSV cars equipped with the dual-fuel system, which unlike conventional LPG systems that squirt vapour into the inlet runners, injects precise amounts of liquid LPG from an injector next to each of the 6.2-litre LS3 V8’s conventional petrol fuel-injector nozzles feeding the eight cylinders.
Compared with gas, liquid provides more accurate fuel metering and cooler combustion for a better burn.
The company claims a 15 per cent reduction in CO2 emissions and up to a 50 per cent cut in fuel costs over pure petrol due to the cheaper price of LPG at about 50 cents a litre, depending on driving style. Highway range can be more than 1000km on the combined petrol and LPG fuel tanks.
Official fuel economy test results were unavailable at the HSV E-Series 3 launch this week, as they were still being done at Holden’s Lang Lang proving ground lab.
HSV admits it began development of the LPI system in 2008 when oil prices spiked alarmingly, pushing petrol prices to $1.60 a litre and raising fears within the company that buyers might be deterred from its V8-powered products.
Left, from top: HSV E3 ClubSport, 'Light Urban Leather' interior, E3 range's standard EDI system, standard touch-screen with navigation and reverse camera, new 'Oracle' instruments.
While the oil price scare subsequently subsided, HSV elected to continue on with the project as insurance against a similar event in future and the prospects of luring drivers who might have previously balked at an HSV car on environmental grounds.
The project marked the first time GM’s high-performance LS3 V8 had been redeveloped to dual-fuel, which meant HSV had to send test engines to the United States for durability analysis.
HSV engineering manager Joel Stoddart said this involved about 900 hours of bench-testing – equivalent to 160,000km of road driving – while chewing through 44,000 litres of LPG.
As well, five test vehicles ran on public roads for two years, in a durability program that included hot-weather testing in the Northern Territory.
He said the main concern for the engineering team was durability of the valves, as LPG was dry and harsh compared with petrol, lacking the latter’s lubrication qualities around the valve seats, especially at high engine revs.
HSV solved the issue by engineering the system to switch back to petrol at between 4000 and 4500rpm, depending on throttle pressure.
The engine also starts on petrol, which is better at cold temperatures, before switching to LPG when warm.
Mr Stoddart said HSV faced a challenge when seeking a suitable fuel management control unit for the system, because no such eight-cylinder CPU existed. In the end, the engineers solved this issue by piggy-backing two six-cylinder CPUs.
HSV managing director Phil Harding said the company had needed to erase the “taxi” image of LPG lest it tarnish HSV’s high-performance street cred.
To this end, the company opened its usually secret development program to public scrutiny at an early stage to demonstrate the performance potential of LPG, along with its reduced running costs and lower emissions.
Mr Stoddart said one of the main goals of the LPI project was to maintain HSV’s high-performance power and torque levels, along with seamless changeover between petrol and LPG when driving.
He said production engines fitted with the system have exactly the same performance outputs – 317kW/550Nm and 325kW/550Nm – as standard petrol V8s.
Although Orbital is said to be developing an LPI system in league with Ford Australia for its Falcon from next year, HSV says its version of the system is unique.
The system costs $5990 for HSV sedan models and $6390 for Maloo. It is unavailable on the ClubSport Tourer R8 wagon, because the LPG tank will not fit.
In the sedans and Maloo ute, the tank holds about 40kg of LPG, for a total maximum weight gain of about 100kg over petrol models.