Sales of hybrids are rapidly outstripping those of electric vehicles (EVs), with experts concerned the developing consumer trend will slow the national reduction in transport emissions.

Hybrids, which combine batteries and electric motors with internal combustion engines, recorded 14.4 per cent of new car sales last month, up from 7.8 per cent in June last year, according to data published by the Federal Chamber of Automotive Industries (FCAI) this week.

By comparison, sales of EVs declined last month for the second time since 2020. The share of new EV sales was 8.3 per cent, falling from 8.8 per cent this time last year.

The latest figures confirm a trend where many new car buyers are opting to ditch standard petrol cars, but choosing hybrid vehicles over full battery EVs.

Petrol vehicles' share of new car sales have fallen from 48 per cent to 43 per cent over the past year. EVs' share has hovered around 8 per cent, while hybrids have climbed into the double digits.

Hussein Dia, a transport expert at Swinburne University, is concerned the resurgent popularity of hybrids will delay mass uptake of EVs, which is bad news for emissions reductions.

Although hybrids are generally more fuel efficient than standard internal combustion engine vehicles, they're far more polluting than full battery EVs.

Some car manufacturers are heavily promoting hybrids in Australia, marketing them as low-emissions cars without "range anxiety", or the worry that an EV won't have enough charge to reach its destination.

"It's not a coincidence this [sales boom] is happening now," Professor Dia said.

"People think they're doing the right thing for the environment, and they're not."

A 'transition technology' that won't go away

The recent popularity of hybrids has come as a surprise to many industry observers.

Hybrids were thought to be well on the way to obsolescence. More than 20 years after the first Toyota Prius and other hybrids appeared on our highways, EV technology has bounded ahead. Many believed the future belonged to cleaner, cheaper-to-run, fully battery-powered cars.

Automakers queued to announce their intention to phase out the production of any kind of internal combustion engine vehicle. 

Then something unexpected happened. Most notably in the US, EV sales slowed while hybrids surged.

US sales of hybrids grew five times faster than EV sales in February this year.

Hybrids come in two kinds:

• The conventional type use regenerative braking to recharge their batteries, which run an electric motor. The internal combustion engine kicks in when the battery is depleted.
• Plug-in hybrids are similar, but the battery can also be charged directly from a power outlet.

Conventional hybrids (which have been around longer) are by far the most popular of the two vehicle types in Australia.

As a result of strong hybrid sales, automakers such as Ford, General Motors, Mercedes Benz and Volkswagen are scaling back or delaying their EV plans.

Professor Dia speculated the recent popularity of hybrids came down to three factors:

• the petrol engine removes anxiety about EV range
• they're generally cheaper to buy than EVs (since they have a smaller battery)
• they're cheaper to run than a standard internal combustion engine vehicle.

"To many people, that's enough to offset the disadvantages, such as a higher purchase price than internal combustion engine vehicles," Professor Dia said.

"I think the public can't ignore the media campaigns from some automakers, and they don't know they are emitting very high emissions."

No need for hybrid 'safety net': EV Council

Although EVs aren't seeing the record growth of 2022 and 2023, experts say the market has merely slowed rather than collapsed.

Monthly sales fluctuate with shipments and are an unreliable guide to consumer demand. The past six months of sales data shows EV sales growth has been almost double that of the overall vehicle market.

"There's a lot of scaremongering around EVs," EV Council CEO Samantha Johnson said.

"The most important thing is petrol car sales is going down. We want a replacement of petrol vehicles into hybrid and battery EV."

The role of hybrids in the transition to zero-emission transport has been a contentious one within EV circles and the broader environmental movement. 

In late 2022, the Greens party and independent senator for the ACT David Pocock pushed Labor to end subsidies for plug-in hybrids from April 2025, arguing their inclusion would be a "de facto subsidy for fossil fuels".

A year later, a Toyota executive said hybrids were a "better fit" for Australian motorists than EVs.

The Japanese automaker drew scorn, but has since been cashing in on the demand for hybrids. In May it announced that, for the first time, more than half of its total sales were hybrids. 

It's increased its share of the Australian market to more than 19 per cent, up from 16 per cent a year ago.

Ms Johnson said it was "great" to see hybrid sales increase but "I would encourage people to move straight into EVs".

Hybrids may allay motorists' EV range anxiety, but improved charging infrastructure meant there was no need for the "safety net" of an internal combustion engine, she said.

"You can move safely to EVs."

Will hybrids delay deep emissions reductions?

Although hybrids are generally more fuel efficient than standard petrol and diesel cars, the data paints a complicated picture for national emissions reductions.

About 10 per cent of Australia's greenhouse footprint comes from passenger cars on our roads.

Most of the hybrids Australians are buying are bigger, heavier SUVs, which cancels out some of the emissions savings.

Robin Smit, director at the research consultancy Transport Energy/Emission Research, said the switch to hybrids would reduce direct exhaust CO2 emissions by about 30 per cent in urban driving conditions.

Battery EVs, by comparison, "are about three times more energy efficient than internal combustion engine vehicles", Dr Smit, who's also a researcher with the University of Technology Sydney, said.

"Our research has consistently shown that the CO2 emissions performance of battery EVs is significantly better than [internal combustion engine vehicles and hybrids]."

Plug-in hybrids are, in theory, more fuel efficient than conventional hybrids, since they can be driven without burning any fossil fuels, like an EV.

But studies show that, in practice, motorists fail to charge them, so the electric motor kicks in less often. Actual emissions of plug-in hybrids can be three times higher than reported emissions (which are based on the assumption car owners will charge their cars), Dr Smit said.

"Hybrid technology is unlikely to deliver the deep reductions that are required to rapidly decarbonise our transport sector and meet our zero emission targets," he said.

Professor Dia said he hoped the popularity of hybrids would fade as EV charging infrastructure improved, prices fell, and model availability improved.

"Prices of EVs are still too high for people and some people are finding hybrids the middle ground," he said.

"The International Energy Agency was forecasting we'd have price parity between battery EVs and internal combustion engine vehicles somewhere by the end of this decade.

"But we're edging closer and I think we'll close the gap before then."