Cars are cooking with gas
LPG is readily available and favours high-mileage drivers with lower running costs
INJECTION has pumped up the credentials of liquefied petroleum gas as a preferred future fuel for cars. That’s the view of the CSIRO, the Federal Government and Australian car manufacturers, who regard LPG as a short-term solution to our reliance on crude oil.
The CSIRO’s Future Fuels report in 2008 projected that electricity, LPG and natural gas (particularly in freight) would lead the way. It predicted LPG would continue to account for about 6 per cent of the transport fuel use for the next decade. The report also noted greater use of electricity and gaseous fuels, such as hydrogen, LPG and natural gas, can be expected to both promote reduced greenhouse gas emissions and improve local air quality’’.
The Automotive Australia 2020 Technology Roadmap, funded by the Australian and
LPG is readily
available and favours high-mileage
drivers with lower running costs
Victorian governments, also identified gaseous fuels as worthwhile short-and midterm investments.
LPG is a cheap, readily available fuel (more than 3500 of Australia’s 7500 service stations have an LPG pump) that favours high
because the lower running costs help offset the cost of buying or converting to LPG.
LPG emits less greenhouse gas than petrol and Australia’s known reserves are projected to last for 20 years.
Nearly 620,000 cars on Australian roads are powered by LPG, according to LPG Australia. Of those, about 200,000 had the LPG system factory-fitted. A government rebate for motorists who buy a new LPG vehicle or convert an existing one has accelerated the uptake in recent years. The rebate is $2000 for a new car or $1500 for a conversion, though the latter falls to $1250 from July 1.
Carsguide’s used-car expert Graham Smith, long an LPG advocate, says the initial cost of the system is somewhere between $2000 and $4500 and modern vapour injection and liquid injection systems can be tuned to deliver power comparable to an equivalent petrol engine. ‘‘ The more you drive the car, the quicker the return on the conversion price,’’ Smith says.
He cites a car using 10L/100km (typically, a Ford Falcon or Holden Commodore) and covering 10,000km a year. With petrol at $1.40, the annual fuel cost is $1400. To cover the same distance on LPG (at 70c and using 30 per cent more fuel) costs $910. The saving will pay off a $2500 conversion (a $4500 system less the $2000 rebate) in just over five years. Travel 20,000km a year and the repayment time is halved.
The latest LPG innovation is phased liquid port injection. HSV uses a dual-fuel version and Ford’s new EcoLPi Falcon will use a dedicated liquid injection system. The LPG is injected into the inlet manifold as a liquid, at which point it vapourises and expands about 240 times. In theory, the expansion cools the incoming air to create a denser airfuel mix as it enters the combustion chamber.
Unlike vapour injection, it doesn’t need a separate engine control processor to regulate the fuel supply.
Smith says the principle has yet to prove effective in all applications. Dedicated systems have had problems with vapour lock and boundary fuelling (where the vapour liquefies against cylinder walls and limits combustion).
The Australian LPG Warehouse disputes this. It says a dedicated LPG liquid injection taxi in Melbourne clocked more than 150,000 with no problems.
Smith says today’s vapou injection systems, such as th expected to be fitted to Holden’s new dedicated LP Commodore, are proven an on a par with the liquid
Conversion: motorists pay up to $4500
for a gas system but for nowreceive a rebate of at least $1500