Proton GEN-2 GSX ecoLogic

"Can I afford not to be driving a Proton GEN-2 ecoLogic?" That’s the question Proton suggests visitors to its website looking for information about its LPG-powered mid-range car should be asking themselves.

LPG (liquefied petroleum gas) is an alternative fuel that can offer significant savings for drivers of cars that normally run on petrol (as opposed to diesel) and while there are all sorts of other factors to take into account when deciding what car to buy, you'd have to say that on the numbers, it's difficult to disagree with Proton's case.

LPG conversions were quite popular a few years back because they were subsidised under the UK government's PowerShift scheme designed to encourage the use of alternative fuels. These grants were abolished in 2005, and since then, drivers have generally had to balance the cost of converting a car to run on LPG - upwards of £1600 according to UKLPG, the trade body for the British LPG sector - against the price advantage of LPG compared with petrol.

LPG prices typically lie in the 50 to 60p per litre range compared with the £1-plus that filling stations are charging for unleaded at the moment. A complicating factor is that the energy density of LPG is a little lower than that of petrol, so it delivers slightly fewer mpg, but this only offsets the price advantage of LPG to a small degree.

Anyway, it's clear that even in the absence of the previous subsidies for equipping and car to run on the fuel, LPG could offer many motorists a financial saving depending on a series of sums taking into account factors such as the cost of the LPG conversion, the period over which they expect to amortise their investment, how many miles they travel each year and so on.

But now Proton has made the maths really easy and tipped the advantage quite strongly in favour of LPG - and the customer - with the ecoLogic versions of its GEN-2. These are sold as LPG-capable cars straight from the showroom (and this is the really interesting bit) at no extra cost compared with the equivalent petrol-only GEN-2 models. Another big advantage of the ecoLogic is peace of mind; an "official" LPG conversion like this one should go a long way to assuage any doubts about the quality of the work carried out or quibbles over warranties and so on.

The only external difference between the LPG-capable GEN-2 and its petrol-only counterpart is a neatly installed second filler cap for the LPG and a small "ecoLogic" badge on the tail.

The LPG itself is stored in a round doughnut-shaped tank that sits in the spare wheel bay under the load area, so opting for the ecoLogic brings little or no penalty in terms of luggage or passenger space. A small combined LED fuel gauge/button mounted on the centre console allows the driver to switch between LPG and petrol operation on the move (the car always starts on petrol), as well as to see how much LPG is left in the tank.

Apart from the fact that it was capable of running on LPG, our test car, a mid-range GSX priced at £10,995 (a more basic version, the GLS costs £9,995), was pretty much the same to drive and to live with as the standard GEN-2.

The 1.6 litre engine isn't especially quick on paper but is subjectively lively and willing. Switching between LPG and petrol is an entirely seamless process producing no hesitation at all, and regardless of the theoretical differences between LPG and petrol in terms of energy density, octane rating and so on, most drivers will be unable to detect any change in the ecoLogic’s performance when switching between the two fuels. The GEN-2's road behaviour, as you would expect, given that Proton owns the sports-car maker Lotus, is sound.

The interior is fairly roomy and Proton has gone a long way to address the main weakness of early GEN-2s - their low-rent interiors. Over the years, beiges and browns have been edged out in favour of the dark greys Europeans tend to prefer when it comes to car interior trim but the biggest improvement has been the adoption of leather trim as standard on the GSX until the end of September 2009 (normally it costs an extra £1,000), which must surely make it by far the cheapest car on the market to provide this sort of luxury. Apart from the abundance of red piping, which feels like the result of Proton trying just a little bit too hard, the result is very agreeable.

Some of the switchgear and surfaces still lag a bit behind the best, but owners can always console themselves that any residual flimsiness might just be the result of Lotus engineers' congenital inability to add weight to their cars (motto: "add lightness").

So, in all, the impressive sums may just persuade some buyers who hadn’t previously considered one of these Malaysian motors to take the plunge, provided they get to hear about it in the first place, of course - Proton's promotion of these cars has been a bit low-key. Of course, it could be argued that going diesel might produce similar savings in terms of fuel costs - and the lack of a diesel engine in its line-up is probably one of the reasons Proton went the LPG route. But the market isn't exactly awash with diesels with prices that start at less than ten grand, and which deliver near-Golf-like space. We are now running an extended test of the ecoLogic in order to assess the precise advantages it provides in terms of running costs, and will bring you the results within the next few weeks.

Car stats

Price: £10,995

Engine: 1.6 litre petrol/LPG

Power: 110 horsepower

Transmission: five-speed manual

Top speed: 118 mph

Acceleration: 0-62mph, 12.6 seconds

Fuel consumption: 39.8mpg (combined cycle, running on petrol)

CO2 emissions: 170g/km (running on petrol)