Ford Falcon G6 E-Gas v Holden Berlina LPG v Honda Accord V6 2008 Comparison

It's a typical spring morning in Melbourne. The wind and rain are blowing from the Antarctic, the Monash Freeway is clogged up like a Macca's addict's arteries, there's a crash holding up the Western Ring and the baggage handling has broken down at Tullamarine.

Jeez, who'd be a commuter? And if the pains of life in the slow lane aren't bad enough, these days we get to pay around $1.50 or more for good old 91RON unleaded - more for the higher octane stuff. I remember the good old days, when petrol was 80c per litre and the V8 was king.

Well, we ain't going back. Yes, there is plenty of promise in our motoring future judging by the billions car companies are chucking at potential propulsion systems, such as hybrid, plug-ins, electric vehicles, fuel cells and so forth. But the fact is the clever future tech stuff is going to take a while to make any sort of impact on our need to get from A to B.

In the interim, does LPG, or liquefied petroleum gas, provide a serious, cost-effective alternative? Or does the answer lie with smarter engine tech, intended to stretch petrol farther? That's what we're here to establish.

Listen to people who know and LPG is the fuel we Australians ignore at our peril. While peak oil can only mean rising prices, LPG is cheap and locally available in abundance.

It has its downsides, of course - less energy bang for your buck than petrol high among them. But it is cleaner burning, and on-going development in next-gen tech - namely, liquid-injection technology - will redress the power-deficit issues.

For now though, both Holden and Ford offer traditional LPG fuelling methods. The Ford's dedicated E-Gas system has been mated with the locally built 4.0-litre in-line six-cylinder Falcon engine since the AUII Falcon of 2000, and is virtually unchanged in that time.

Holden reintroduced an LPG dual-fuel option for Commodore in 2006, then chopped the pricing last August to make it more competitive. It's available only with the less powerful version of the 3.6-litre Alloytec engine that's assembled at Port Melbourne.

That means a limited number of VE variants to choose from, so we've plumped for the family-oriented Berlina. The G6 is similarly aimed at families, so that's the E-Gas version of the new FG Falcon we've selected for this comparison.

But the days of a Falcadore comparo answering most questions for most people are definitely over. That's why the latest full-sized Honda Accord has been added to this mix. It's not LPG-powered, it's not rear-wheel drive and it's not locally built, but it is pitched very much as a Falcon/Commodore rival.

It now has a 3.5-litre V6 engine that places it within cooee on capacity, ahead in terms of power, and in its own league when it comes to sophistication.

Okay, the two locals aren't exactly prehistoric in their technology, but the Honda's edge is a clever feature called Variable Cylinder Management. VCM allows the engine to run on three, four or all six cylinders to optimise fuel efficiency.

Despite being around 500cc bigger than its predecessor, Honda claims VCM helps the 3.5 to an official combined average of just 10L/100km, compared to 10.6L/100km for its forebear.

Factor in a $38,490 asking price and, superficially at least, the Honda appears to kick butt. However, take into account the various rebates available for privately purchased LPG-fuelled vehicles and the 80c per litre differential between 91RON and LPG prices (in Melbourne in mid-October) and the two locals quickly look more competitive.

Check the table below, but effectively the G6 is $40,390 and the Berlina $40,690 once the rebate cheque arrives. And sticking to official consumption figures (G6 at 14.9L/100km; Berlina 15.5), the LPG locals gouge another $500 or so out of the Honda's advantage over 20,000km of driving. Mind you, the equation for the Commodore doesn't look so good at its 11.7L/100km petrol average.

Okay, so that's the official version; we're obviously more interested in a real-world results. So while our ride and handling circuit and V-Boxed performance times are still very much part of this plan, the opening day of our comparison is devoted to criss-crossing the city and suburbs in search of traffic lights, gridlock and real-world fuel figures.

Our route starts in the city's north, then loops its way in and out of the city several times before reaching our first refuel at the Westgate Bridge four hours and 150km later.

In raw terms the Honda's 10.2L/100km is clearly the best result, but both the Holden and Ford significantly undercut their claimed LPG averages at 12.1 and 12.4L/100km respectively. Emphasising the gulf in fuel prices, the combined refuelling cost of the G6 and Berlina is less than that of the Honda.

Mind you, the Honda's drivetrain has more going for it than a transitory fuel-consumption advantage. In these stop-start conditions it's clearly superior in terms of smoothness and quietness of response. There's no hint of VCM operating, apart from an 'Eco' light on the dash. It feels at least one generation ahead of its rivals.

The E-Gas is the only Falcon sedan that still employs the old four-speed auto. But because the engine has the most torque here (371Nm) there's plenty of good old-fashioned grunt to cover over most of the 'box's inadequacies. There's also gruffness when cold, a tendency to vibrate through various patches of the rev range and nothing like the civility, nor the top-end of the latest (greatest, and last) 195kW iteration of Ford's petrol I6. No surprise when you realise the E-Gas has the least power here at just 156kW.

The Commodore offers 175kW and 325Nm with LPG, rising to 180kW and 330Nm when switched to 91RON. Either way, this is by far the least agreeable drivetrain. When revved it's excessively noisy in a really ugly, strained way. And the ancient 4L60E four-speed auto is worse than ever with its hesitant and thumping shifts.

What a contrast to the rest of the VE package. The Berlina rides beautifully in a tautly controlled way, has large, supportive adult-sized seats and a massive amount of passenger space. Its steering is communicative and accurate.

Ford's E-Gas Falcon not only misses out on standard fitment of curtain airbags as - controversially - does much of the FG range, but it's alone in making do without either traction or stability control.

The FG looks great around the dashboard, although the centre stack's modern style is let down by small buttons with tiny graphics. That's contrasted with the Holden's jumbo controls and old-fashioned layout, while the Honda's protruding stack offers operating efficiency somewhere between the two.

The Ford's interior is the lightest and brightest overall, the front-seat backrests the most supportive and the rear seat highest and flattest in the base, giving the passengers a better view. Fitting two full-sizers in the rear isn't a challenge for these cars, although the middle-rear passenger wouldn't find any of them comfortable.

Ride comfort is definitely a G6 forte, along with light, eager steering. It's a winning combo around town.

Surprised it out-performs the Honda? Well, the Accord's ride is terse at low speeds, tending to bob and vibrate rather than pamper and cosset. Nor does its soulless steering offer anything more than an approximation of direction. Its 11.2m turning circle isn't the worst, though, bested by the 11.0m Falcon but ahead of the 11.4 metres of the Commodore.

The Honda does offer one clear advantage: in the boot, where it's unencumbered by fuel-related paraphernalia. Both the Holden and Ford are badly compromised by their LPG tanks. The Ford's occupies the spare wheel well which in turn means the spare itself ends up in the boot, cutting capacity from 535 to 408 litres.

The Commodore's cylindrical tank sits in the boot, cutting space from the petrol version's 496 litres to 325 litres. It also means the end of the ski-hatch.

The morning cruise also gave us the chance to peruse the exterior styling of these three cars from most angles. The Berlina is perhaps the least impressive VE, but it remains simply attractive, the G6 looks good riding on 17-inch alloys while the Accord is messier, with more creases and plenty of overhang.

We move on to the afternoon loop, this time with the Holden running on ULP. Now, the traffic is lighter and there are more opportunities for constant throttle, until we hit the 5:30pm stop-start commuter rush heading north out of the city.

The free-flowing conditions suit the Honda's VCM, and it shows at the pump, the Accord recording a stellar 8.3L/100km. The Falcon also does well, staying under its official average at 13.5L/100km. But the Holden blew out beyond its claimed ULP average to 12.5L/100km, barely heading the E-Gas Ford.

Doing the sums for the day tells us the Honda consumed the least fuel yet was the most exxy to run. The Ford has used the most fuel yet been the cheapest. The Holden sits in between on both counts.

Day two and our first chance to wind the cars out, but the Falcon immediately objects. Bang, bang! It sounds like a couple of pistons have fired out of the block. No, it's actually LPG igniting as we hit the rev limiter. The best we can surmise is spark is being retarded but not fuel and the excess is igniting and causing the airbox to jump on its sprung mounts.

Apart from this unexpected and unwanted party trick, the Ford tackles the country combination of freeways, highways, byways and dirt roads with an aplomb other members of the FG range have already displayed in Wheels testing this year. Its well-executed chassis makes us feel less nervy - if not happy - about the absence of traction and stability control. The steering and ride qualities noted in suburbia are just as obvious here, too.

The Honda's ride quality, meanwhile, is clearly improving as speeds rise. It's also the quietest here, proving its refinement isn't restricted to its engine.

The Holden is the noisiest and its powertrain remains a poor excuse for a boat anchor. But the chassis is becoming more and more admirable. While the Ford is more eager on turn-in, it sometimes requires a couple of nibbles at the wheel to stay on line. The Holden just turns and sticks beautifully, inspiring with its confidence and ability. The ride sharpness apparent over small bumps irons out as the challenges become more severe. It's easy to forget you're hustling along in a 4.9m, 1.8-tonne full-size rear-wheel-drive sedan. What a ripper.

But not at Tooradin airfield. Both the Commodore and Falcon are embarrassed by the cleaner, harder-running Accord. Be it from a standing start or kickdown, the advantage is stark.

No doubt top-end power is an issue for the Ford, while weight undoubtedly holds the Commodore back, as its LPG storage system adds an extra 100kg. The compromises inherent in tuning an engine to run on two different fuels also becomes apparent as the Commodore pulls more cleanly in the top-end running on LPG than it does on petrol.

But it was the Honda's turn to finally vacate top spot when we reached the last refuel. While still the most economical, its 12.0L/100km on the country loop no longer stood out as something special. The Holden ran it close on petrol, and, as per the previous morning, edged out the Ford when running on LPG.

So what does it all add up to? The Honda is definitely the smoothest, most civilised car to drive and the cheapest to buy, but it's also the most expensive to refuel. The Falcon has a great ride and a pleasing interior, but the safety equipment list and boot-space compromises are unacceptable.

The Commodore is also handicapped in the boot, but more tellingly in the engine bay where its noisy engine is shackled to a transmission miles beyond its use-by-date. For drivers, this is perhaps the best chassis, but the dual-fuel Holden fails as a package.

So which one to choose for the urban battlefield? Well, if you base the decision purely on long-term refuelling costs, then the Falcon and Commodore are pretty much a toss-up. But broaden your perspective and the Honda comes to the fore.

So buy the Honda now, then hope like hell Ford and Holden's next-generation LPG cars are better-developed, more appealing propositions in a few years' time when petrol is even more expensive.

Images: Cristian Brunelli