The US Department of Transportation (DOT), Environmental Protection Agency (EPA), and California Air Resource Board (CARB) have taken the first step in a mid-term evaluation of the national programme for greenhouse gas emissions and fuel economy standards for light duty cars and trucks with the release of a draft technical assessment report (TAR) for public comment.

"The release of the TAR delivers on a commitment that EPA made in 2012 as part of the rule making establishing a national programme for the 2017-2025 period. The draft TAR covers model years 2022-2025," the three agencies said in a joint statement.

The draft TAR shows automakers are rapidly innovating and bringing new technology to market and that will be able to meet the MY 2022-2025 standards established in the 2012 rule making with a wide range of cost-effective technologies.

"Moreover," the statement said, "it indicates that these standards can be achieved by relying primarily on advanced gasoline vehicles. The report also shows that manufacturers will be able to meet the stricter standards at similar or even a lower cost than was anticipated in the 2012 rule making, with substantial savings on fuel costs for consumers."

"[The] draft report shows that automakers are developing far more technologies to improve fuel economy and reduce greenhouse gas emissions, at similar or lower costs, than we thought possible just a few years ago. And they are adopting these fuel-saving technologies into their fleets even faster than anticipated," said Janet McCabe, acting assistant administrator for EPA's office of air and radiation. "This is simply great news for consumers, manufacturers, workers and the climate."

National Highway Traffic Safety administrator Mark Rosekind said: "The draft report supports that the administration's fuel economy programme can continue to incentivise innovation and reduce fuel consumption while also ensuring that consumers can continue to choose the vehicles they want to drive. The agencies welcome public comments to assist the agencies' analysis and decision making."

"After almost four years of close collaboration on the draft technical assessment report with our federal partners, the conclusions are clear: costs are lower for many technologies than we originally thought, market uptake is strong, and expected consumer benefits remain high," said CARB chair Mary Chols.

The national programme is designed to enable consumers to choose the car or truck they want while ensuring that the vehicles they select will reduce carbon emissions and save on fuel costs. The programme was developed jointly by the EPA and DOT, in coordination with CARB, and it applies to passenger cars and light duty trucks to the end of model year 2025. It requires manufacturers to improve average fuel efficiency and reduce average greenhouse gas emissions over time.

In recent years, and responding to the standards established in the national programme, automakers have been rapidly adopting fuel-efficient technologies like turbocharging, engine downsizing, more sophisticated transmissions, vehicle weight reduction, aerodynamics, and idle stop-start, along with improved accessories and air conditioning systems.

Over 100 car, SUV, and pick-up truck models already on the US market meet 2020 or later standards, suggesting automakers should be well-positioned to meet future average standards through additional application of those technologies.

The draft report is the first of several steps the agencies will take as part of assessing the standards for new vehicles in the 2022-2025 model years. The report itself is not a rule making and does not change any of the existing requirements under the existing national programme.

The national programme does not set a single fuel economy target number for all vehicles but instead establishes separate footprint-based standards for passenger cars and light trucks. A manufacturer's compliance obligation depends on the mix of vehicles that it produces for sale in each model year – if a manufacturer produces mostly larger vehicles, its average standard will be less stringent than if it produces mostly smaller vehicles, reflecting the reality that smaller vehicles often have better fuel economy and lower carbon emissions than larger vehicles. This approach ensures that consumers can continue to choose from the full range of fuel efficient vehicles on the market, and at the same time, it improves efficiency and emissions for all types of vehicles.

While the draft TAR analysis focuses on the MY 2022-2025 standards, the report also shows auto manufacturers over-complied with the standards for each of the first three years of the programme and, in 2014, outperformed the standards by 1.4 miles per [US 3.9-litre] gallon.

This occurred during a period during which the automotive industry has seen six consecutive years of sales increases and a new all-time sales record in 2015, reflecting positive consumer response to vehicles complying with the standards, the three agencies said.