Subaru says Stella "clean" but Drive.com says it's a "dirty" EV #environment

Who do we believe?

My confusion is all about the Subaru Stella EV. Apparently Subaru (in a press release) says: Based on power supplied from a coal-fired power station, STELLA produces an estimated 12.5 kilograms (kg) of Carbondioxide (CO2) per 100 kilometres of travel, compared to 20.24 kg of CO2 for a typical 2.0 litre small car.

So it's cleaner, no risk.

But Fairfax via its Drive.com site says the opposite (seemingly): Recent research has shown that electric cars don’t necessarily reduce the carbon footprint. Subaru recently said its electric Stella would account for 20 per cent more carbon dioxide emissions if recharged from a coal-fired power station.

Did Subaru say that? I didn't see that. But wait...

If we pull that apart a bit... Subaru compared the Stella, a small - in fact quite small, if heavy at 1,000kg - car, with a much larger "typical" 2.0l car. I assume they mean larger, because Subaru's 2.0l cars are "typically" Imprezas and the like... so it's not apples vs apples, is it? If we compared tiny Stella with a micro car with a 660cc engine we'd probably see around 10kg of CO2 per 100km, which is indeed somewhat less than the Stella and backs Drive.com up. You'd probably pick the petrol car over the EV for environmental reasons.

I do wonder though if Drive.com actually thought it through. It's not actually what Subaru said, although it's what we can derive from their statement. They are being a bit narky here, to use the Aussie idiom. Indeed Drive.com had a go at Subaru when it earlier reviewed the Stella, here: One thing the Stella not completely free of, though, is guilt. Despite no greenhouse emissions coming from its electric engine, Subaru says using Australia's coal-fired electricity would produce about 125g of carbon dioxide for each kilometre travelled in the Stella - almost 20g more than a Toyota Prius hybrid car that uses a 1.6-litre petrol engine alongside its electric motor.

Interestingly I think they meant 1.5-litre rather than 1.6, but they are the experts so let's go with that. So we can assume (so many assumptions!) Drive.com is actually comparing the Stella with the "1.6l", 1325kg Prius, which opens up a can of worms indeed.

All of these things are worked out by average use, of course, but nothing is ever really average, and it's not just about use. We need to look at the manufacturing footprint, too. If you are heavy-footed in your somewhat porky Prius, what happens to your carbon footprint? It goes up, obviously, and probably more so than an EV (better check that). And what of the extra complexity of the petrol/electric hybrid, with 2 power sources, a petrol tank and batteries? Which of these 2 cars (the Stella EV vs the Prius "1.6") is less resource-hungry - and has the lesser overall carbon footprint - to make and maintain? I'm guessing (so much guesswork!) the Subaru EV wins hands down if we look at it that way; but there's no denying, either, that a 660cc petrol Stella will beat both by a wide margin.

Of course none of this really stacks up, if it's not what you need in a car. You may drive short distances and the Stella EV will be ideal. Or you may travel long distances at a steady speed and can make the most of a hybrid's advantages. Indeed the Stella may be a perfect fit for me but too small for you. It all depends.