Are Electric Cars Really ‘Greener’ Than Petrol Cars?

Credit: Kindel Media

Electric vehicles (EVs) are commonly suggested as a solution to environmental issues, But before you rush to trade in your trusty petrol car, it’s worth asking: is that shiny new EV really better for the planet? Let’s take a closer look at the numbers - and the bigger picture. 

The Carbon Break-Even Point – When an EV Pulls Ahead 

An important factor to consider when comparing electric cars to petrol cars is their embodied emissions. Embodied emissions are the greenhouse gases released before a car even hits the road - mainly from manufacturing, including the energy and materials used to make the battery. For EVs, battery production is especially energy-intensive, which is why they generally start with a higher carbon footprint than petrol cars. 

Once an EV is on the road, it typically produces fewer emissions per kilometre -especially in NZ, where most of our electricity comes from renewable sources. Over time, these lower “running” emissions work to offset the higher emissions from manufacturing, and when comparing the emissions from burning fuel in a petrol car.  

Studies suggest that, in NZ conditions, an electric car reaches its carbon break-even point after around two years of driving. After that point, every kilometre you drive in an EV generally produces significantly less carbon than burning petrol or diesel - making it the cleaner choice over its lifetime. 

Beyond Carbon: The Other Environmental Costs 

But carbon isn’t the whole story. Life Cycle Assessments (LCAs) - which measure the total environmental impact across a range of factors - reveal some areas where EVs can fall short: 

• Weight and Wear: EVs are often heavier than petrol cars because of their large battery packs. That extra weight puts more stress on tyres and roads, increasing wear and tear. Over time, this can release more microplastics and particulate matter into the environment - even though regenerative braking often reduces brake wear. 

• Resource Extraction: EV batteries rely on critical metals like lithium, cobalt, and nickel. Mining and refining these materials can damage ecosystems, pollute waterways, and raise ethical concerns - especially if the supply chain isn't responsibly managed. 

The Case for Keeping Your Old Car 

Believe it or not, one of the most environmentally friendly things you can do might be... nothing. Keeping your well-maintained petrol car running a little longer avoids the environmental costs of building a new vehicle altogether. 

Repairing and maintaining what you already own means fewer raw materials, less manufacturing energy, and reduced waste. In fact, across many impact categories beyond just carbon, sticking with an older vehicle can leave a smaller footprint than switching to a brand-new EV - especially for low-mileage drivers. 

 

What We Still Don’t Know 

Despite all the data we do have, there’s still no full, head-to-head Life Cycle Assessment comparing a well-maintained petrol car with a new EV in the specific context of New Zealand. Without that kind of study, it’s hard to say definitively which option comes out on top across every environmental measure. 

So, What’s the Best Choice? 

Bike, walk, or take the bus. But if you do need to drive your own car, EVs do offer real carbon savings over time, particularly in countries like NZ with mostly renewable electricity. But they’re not a perfect solution. Mining impacts, battery production, and added vehicle weight all come with trade-offs. 

Until more detailed research becomes available, the smartest move is to make your next car—whatever it is—as environmentally responsible as possible. Choose efficient models, look for brands using ethical supply chains, and keep any car you own in good shape. 

And if you don’t drive much, the greenest car might just be the one that’s already in your driveway. 

If you want to compare the lifetime carbon impacts and the lifetime cost in dollars of your choice of cars, we can help you calculate that with a comparison. Get in touch.  

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