LPG Holdens set new CO2 benchmark

Holden today served a new stroke in its campaign for a sustainable alternative energy future. With the launch of the new mono-fuel LPG variants of Commodore and Caprice, the company can now provide consumers lower running costs for its large-car range to a level well below those of a conventional 1.8-litre small car.

And the price of purchasing the Commodore with the new LPG system remains affordable — just an extra $2500, reducing to $500 only, for private buyers applying for the $2000 government rebate.

"Many Australians still value the benefits you get from a large car — the comfort, the convenience — that Commodores offer. And basically, by reducing fuel costs we want to make this choice easier for them," said Richard Marshall, Holden's Director of Energy, Environment and Technology during a press conference for the new variants.

"The LPG Commodore — the dual-fuel one — was a great stepping stone; it provided many benefits, however it also presented some compromise. With the dedicated system that we're launching today, there is no such compromise. It's a new, purpose-built vehicle, [and] delivers benefits in vehicle performance [and] spaciousness that a dual-fuel system simply can't do. So by engineering the system for a single fuel it's allowed us to optimise the performance, the fuel economy, the running costs and the environmental outcomes."

Key to the new system is the vapour injection hardware — as opposed to the liquid injection system adopted by Ford for the Falcon. According to Holden, vapour injection provides better economy, lower emissions and easier starting. In fact, one aim of the development program was to offer buyers a 'seamless' LPG-fuelled vehicle that drove indistinguishably from a petrol variant. Holden has even managed to make the issue of slow starting go away with the new system.

"Overall data supports the fact that vapour injection results in lower fuel consumption — and therefore lower CO2 emissions, when compared to liquid injection," explained Holden's Brian McMurray, Program Engineering Manager for Global RWD.

"Vapour injection uses fuel more efficiently. The reason for this? Vapour has lower pumping and parasitic losses, when compared with liquid injection."

"Vapour for us was the right solution."

According to McMurray, Commodore variants running the Vapour Injection LPG system are already ahead of the Euro 6 emissions standard and have been rated at 4.5 stars by the Green Vehicle Guide. An Omega with the mono-fuel LPG system could cost as little as $1300 a year to run, versus over $2000 for the Toyota Corolla with 1.8-litre engine.

The downside to Holden's chosen Vapour Injection method is that it cannot match the Falcon EcoLPI for power and torque. To offset this in part, Holden only offers the LPG option with the 3.6-litre V6. Even Omega and Berlina models are fitted with the larger displacement engine, leaving the 3.0-litre V6 for petrol applications only. Despite the extra capacity, the LPG engine develops just 180kW — 10kW less than the 3.0-litre petrol engine. But torque peaks at 320Nm, 30 more than the 3.0 and 30Nm less than the petrol 3.6. In contrast, the Ford engine develops 198kW of power and 409Nm of torque.

With an extra 400cc of displacement the Falcon XR6 EcoLPI achieves almost the same combined-cycle fuel consumption as the SV6 LPG (12.4L/100km for the Ford, versus 12.3 for the Holden) and emits precisely one gram more CO2 in the same test — 199g/km for the Ford, 198g/km for the Holden. The margin between Falcon XT and Omega is significantly wider though; 11.8L/100km to 12.3L/100km and CO2 emissions of 189g/km to 199g/km, both favouring the Holden.

The differences in power, torque, fuel consumption and CO2 emissions seem to be largely a case of swings and roundabouts, but the Commodore has one particular advantage over the Falcon — it starts faster. In fact, there's no difference in starting time from petrol to LPG variants of the Holden, McMurray told motoring.com.au.

"There is no worst case. Either under hot or cold conditions the car will start immediately. There is no delay cranking with our system."

Holden has subjected test vehicles to a cumulative development program of 1.3 million kilometres over two and a half years. Based on pump prices as of December, Holden claims that an LPG Commodore could be driven from Melbourne to Sydney for just $65 — and the car can theoretically achieve a 700km range based on the official combined-cycle fuel use figure.

For the change to LPG consumption, the V6 now has hardened valves and valve seats, with modified heads and inlet manifold. With a higher octane rating than petrol, LPG allowed Holden engineers to specify a compression ratio of 12.2:1. Holden claims that its LPG vapouriser, which heats the gas immediately prior to injection, is a first for an engine of this size built by an original equipment manufacturer (OEM) anywhere in the world.

The engine drives through a revised (6L45) six-speed automatic transmission introduced with the MY12 Commodore range and available with the petrol engines also.

Fuel is stored in an 84-litre aluminium tank mounted under the floor and behind the rear axle. Adoption of a single-exhaust system to accommodate the tank means the Commodore's weight distribution is effectively unaltered. Holden offers buyers an inflator kit as standard for all LPG vehicles. The kit maximises boot space and provides what Holden marketing executive Kristian Aquilina called "the white shirt option". For those who prefer a spare tyre, there's a spacesaver spare option that sits on the boot floor of the sedan or, deflated, sits upright in the driver's side of the Sportwagon's luggage compartment.

Holden is rolling out a limited edition model, the Commodore Equipe, to entice private buyers to take up the LPG option. Available in both sedan and Sportwagon bodystyles, the LPG-fuelled Equipe is based on the Omega specification, but adds 18-inch alloy wheels a rear view camera, rear park assist, leather appointed seat trim, leather-bound steering wheel and front fog lamps with chrome accents.

Lastly, for Caprice buyers, Holden is offering the long-wheelbase sedan with LPG at no extra cost for a limited time. And those (private) buyers can purchase the Caprice and still apply for the $2000 government rebate.

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