ANN ARBOR, MI – Expect a final federal fuel-economy rule for 2025 within days, National Highway Safety Traffic Admin. chief David Strickland says, while declining to specify whether it will remain the earlier 54.5 mpg (4.3 L100/km) proposed target.

“We’ll wait and see,” he says of the final corporate average fuel economy, which if it remains at 54.5 mpg would be the largest increase in U.S. history and one of the most ambitious such goals in the world.

It also would equate to a carbon-dioxide emissions level in 2025 of 163 g/per mile, according to the Union of Concerned Scientists (UCS).

The final rule for 2025, which comes on the heels of an earlier record hike in fleet fuel economy to 35.5 mpg (6.6 L/100 km) by 2017, will be released “very soon,” Strickland tells WardsAuto on the sidelines of a U.S. Department of Transportation event here launching the world’s largest-ever road test of connected-vehicle safety technology.

“Right now we are just finishing up our interagency work,” he adds. “Our expectation is days rather than weeks. It is a landmark and historic rule, and we have lots of details to finish up.”

Auto makers generally have endorsed the 54.5-mpg mark, which would double the efficiency of cars and trucks at today’s standards.

However, during negotiations with NHTSA and the Environmental Protection Agency in recent months, they won a key “mid-term report” caveat, where stakeholders will re-examine how well the rules are working at the halfway point.

One concern is whether the coming technologies anticipated to save fuel and curb CO2 emissions will have advanced enough over time to keep up with the tightening regulations.

The new rules are expected to cost auto makers nearly $160 billion to implement.

U.S. dealers and some foreign auto makers and expert analysts do not like the 2025 rule, saying it will make cars too costly for average Americans and that the regulations favor the Detroit Three truck makers. If gasoline prices do not increase alongside the new strict standards, car buyers will drop out of the market and shock the economy, they add.

Backers  says the new CAFÉ rule will generate $300 billion in extra revenue for the U.S. auto industry, put an estimated $200 billion of fuel savings into consumer pocketbooks and create 500,000 new jobs.

The UCS estimates the 2025 CAFE rules will save 1.5 million barrels of oil a day, or about 23 billion gallons (87.1 billion L) of gasoline annually by 2030 and trim CO2 emissions 280 million tons (254 million t).

Strickland’s comments come after USDOT Secretary Ray LaHood announces here a $25 million, yearlong program connecting 3,000 cars, trucks and buses with wireless technology enabling them to communicate with one another in real time to avoid crashes.

The University of Michigan Transportation Research Institute will manage the pilot program, which will rely on everyday people driving their daily routine around the university campus located west of Detroit.

“This is a very big investment in America, an investment in the automobile industry and in common ordinary citizens,” says LaHood, flanked by Michigan Gov. Rick Snyder, local politicians and university research leaders.

Data from the project, such as how the cars share information with their drivers and the transportation infrastructure, will be examined afterward to determine how regulators and the industry can proceed toward implementing the systems in production vehicles.

LaHood says no plans currently call for regulating auto makers to include the systems in their vehicles, a costly proposition given the technology’s cost today. It also would require a massive investment in infrastructure technology, such as stoplights and crosswalk lights.

“We’re nowhere near making a rule,” LaHood says. “There’s been no discussion to that.”

Some of the technologies used in the project include forward-collision warning, lane-change warning and blind-spot detection, emergency electric brake-light warning and intersection-movement assist. Intersection-movement assist warns the driver when it is unsafe to enter an intersection.

jamend@wardsauto.com