America's Environmental Protection Agency announced a series of new regulations on Thursday to provide automakers more time to cut emissions from new vehicles and to give them additional credits for environmentally friendly technology.

The rules would still see electric and hybrid vehicles make up more than two in three new cars sold in the country by 2032.

But the peak lobby group for Australian car manufacturers said changes in the US should be a lesson to local policymakers that brands needed more time to supply low-emission vehicles and rushed changes could be a "disaster".

The US agency will phase-in the new rules to limit vehicle emissions between 2027 and 2032, and will include provisions to recognise environmentally friendly choices in air conditioning units, lighter vehicle weights, and better tyres in the scheme.

Despite a slower implementation, the rules would see a similar outcome by 2032, with electric cars making up 56 per cent of new vehicle sales, rather than 60 per cent, and hybrid electric vehicles representing 13 per cent.

The agency said the changes would cut 6.3 billion tonnes of carbon from transport and provide $US13 billion ($19.6 billion) in public health benefits.

"With transportation as the largest source of US climate emissions, these strongest ever pollution standards for cars solidify America's leadership in building a clean transportation future," EPA administrator Michael S. Regan said.

The US changes come as the federal government considers the final design of its fuel-efficiency standard that is expected to be introduced to Australia in January 2025.

A group of three independent politicians expressed their support for the government's proposed standard at Parliament House in Canberra on Thursday, with MPs Monique Ryan, Zali Steggall, and ACT Senator David Pocock posing among empty barrels and petrol tanks covered in real $50 bills to drive home their point.

"The crossbench stands ready to act in the best interests of Australians, not the best interests of the fossil fuel industry," Mr Pocock said.

"We know whilst it's played an important part in our economy, it's time to transition out of."

But Federal Chamber of Automotive Industries chief executive Tony Weber said changes to the US laws vindicated its argument that car makers needed more time to deliver efficient and low-emission vehicles in Australia.

"A vehicle-efficiency standard is a major step for Australia and we should take the time to ensure that car companies have sufficient time to increase the supply of zero and low-emission vehicles into the local market," he said.

"Rushing to introduce a scheme in just nine months time without learning from the US experience is a recipe for a disaster in Australia."

The lobby group has argued for significant changes to Australia's proposed New Vehicle Efficiency Scheme, including a slower start, smaller penalties for exceeding emission limits, the introduction of "technology credits," and the removal of SUVs from the passenger vehicle category.

Mr Weber said the US scheme also included consumer subsidies for electric vehicle purchases and financial incentives for manufactures to build electric cars locally, which the Australian government should consider.

However, the FCAI has recently experienced opposition to its position on a fuel-efficiency standard, with electric car makers Tesla and Polestar resigning their membership with the group over its commentary, and Volkswagen resigning from its policymaking committee.

Australian Associated Press