Just what does "green" mean? Aside from being the colour of frogs, grass and vegies that the kids refuse to eat, it has also become a catch-all catch cry for anything environmentally friendly.
In vehicular terms, a green hue tends to attach most frequently to electric and hybrid powered cars - in the process often conveniently overlooking several key factors.
They include the heavily industrial methods required to build the battery packs that sustain electric vehicles (EVs) and hybrids.
But critics of EVs often conveniently overlook the fact that the refining process that produces petrol and diesel isn't without environmental impact, either.
There are also plenty of petrol- and diesel - powered cars that use advanced turbo-charging technology to generate surprising power from startlingly little fuel use.
The fact is that every car - taking into account its manufacture, running and ultimate demise and disposal - has a significant environmental impact.
Some, though, are better than others for a variety of reasons, so here are the top five picks.
Yes, it's an electric car. Yes, it has a 294-kilogram lithium-ion battery pack. Yes, it can accept its electrical charge from CO2-belching sources.
Yes, it could run out of power and leave you stranded on the side of the road. And yes, it's exorbitantly expensive for a compact hatch.
But for buyers who carefully match their lifestyle to their car choice (that is, never plan to drive more than 150 kilometres in a day), who are prepared to pay extra for ''green'' electricity generated from hydro or solar power, the Leaf offers substantial rewards - not the least of which is the joy of never having to visit a service station.
It's a surprisingly sensible and thoroughly practical five-door hatchback with space for four adults and a boot big enough for the shopping. A funky, futuristic-looking dashboard dominates the driver's view and there's ample urge when you prod the accelerator courtesy of an 80kW electric motor and a single-speed auto gearbox that delivers all its torque from idle.
It takes about seven hours to fully recharge, which delivers up to 160 kilometres in range. Standard equipment includes keyless entry and start, climate control, satnav, rear parking sensors, auto headlights and wipers, six airbags and unlimited smugness.
TOYOTA PRIUS V
The Toyota Prius C is based on the Yaris's city hatch it's well equipped, with seven airbags and a rear-view camera. But as hybrid technology goes more mainstream, the other big news is the addition of a seven-seater. The Prius V is a regular Prius with a bigger body and a third row of seats.
Its official fuel use of 4.4 litres of premium unleaded per 100 kilometres is just 0.5L/100km greater than the smaller car it's based on, although this would increase with seven bodies on-board.
The V flips and folds with the best people movers, with Toyota claiming the split-folding and stowable two rear rows can create 64 different combinations. The second row is spacious enough for adults, and the snug third pew is best left for children only.
The combination of the same 1.8-litre petrol engine, electric motor and continuously variable transmission as the regular Prius gives a satisfactory response, although engine noise can be quite intrusive at higher revs.
There's also plenty of equipment, including a reversing camera, Bluetooth with audio streaming and blinds in the rear windows, not to mention the seatbelt warning indicators for all seven seats.
The French manufacturer's mid-sizer isn't an obvious candidate for green glory, with style and comfort seemingly higher on the priority list than eco-credibility.
But peering deeper into the spec sheets delivers a surprise. The 508 Active eHDi will also take you extremely far on a single tank of fuel.
A 1.6-litre turbo diesel engine (82kW/270Nm) incorporating a stop-start function and brake energy regeneration uses an official 4.4L/100km. Combined with a 72-litre fuel tank, the Pug could take you up to 1636 kilometres between service stations.
Diesel-powered cars typically get short shrift in green lists due to noxious emissions, but emissions of just 115 grams of CO2 a kilometre beat Toyota's petrol-electric Hybrid Camry, while a particulate filter catches some of the nasties associated with diesel emissions.
The eHDi model is available exclusively as a sedan in the basemodel Active specification, but still includes dual-zone climate control, rear parking sensors, a Bluetooth phone connection with audio streaming, auto headlights and wipers, daytime running lights, leather/cloth sports seats and six airbags.
Once notorious for having one of the thirstiest compact SUVs around, Mazda has flipped its fortunes by replacing the CX-7 with the smaller, lighter and more efficient CX-5.
The CX-5 is the first model to receive the full suite of Mazda's ''SkyActiv'' technologies, including lighter and stronger chassis underpinnings, the company's most fuel-efficient petrol and diesel engines, and all new transmissions designed with efficiency in mind.
Petrol models feature a 2.0-litre, four-cylinder engine with a slightly anaemic 114kW and 200Nm that is rated at 6.4L/100km.
Mid-spec Maxx Sport and range topping Grand Tourer get the option of a 2.2-litre, turbo diesel four-cylinder engine (129kW/ 420Nm) running at an official 5.7L/100km.
The CX-5 may lack the concept car-like good looks of its predecessor but more than makes up for it with a quality feel throughout the cabin, which is deceptively spacious.
A driving experience that makes a good fist of living up to the brand's ''zoom zoom'' mantra trades off some ride refinement, however. Included on all models is push-button start, Bluetooth with wireless audio streaming, cruise control, reversing camera and six airbags.
Big SUVs are frequently dismissed as environmentally irresponsible, with their massive footprint and heavy all-wheel-drive running gear conspiring to deliver a mighty thirst.
But some family-sized prestige options are in the process of rendering old preconceptions obsolete, with fuel use that undercuts some small cars.
Lexus set the standard in 2005 when it hybridised its RX softroader, which was recently updated.
The RX450h pairs a petrol-powered 3.5-litre V6 engine with three electric motors, generating up to 220kW and 317Nm but sipping just 6.3L/100km - a deeply impressive figure for a vehicle weighing more than 2.1 tonnes.
Engine stop-start technology and regenerative braking make it a good companion for urban driving, although a continuously variable transmission (CVT), with its unique power delivery, takes getting used to.
With the electric motor making its torque available from a standstill, the RX450h jumps smartly from stationary.
On the highway, the big Lexus gets along with surprising ease thanks to its flexible mid-range torque.
However, its low ride height means it cedes off-road ability to its rivals, and you're always reminded of its weight through bends.
Tthe RX450h Luxury - gets leather seats with electric adjustment, satnav, push-button start, eight airbags, dual-zone climate control, front and rear parking sensors, and automatic headlights.
It's marginally thriftier than the Mercedes-Benz ML 250 CDI BlueTec, which ekes economy of 6.4L/100km out of a 2.1-litre four-cylinder turbo diesel engine making only 150kW, but also a chunky 500Nm of pulling power.
- Sydney Morning Herald