US regulators announced on Friday stricter rules on vehicle emissions and a requirement for low-sulfur gasoline as part of President Barack Obama's efforts to reduce pollution.
The Environmental Protection Agency's proposal would require a 60 percent reduction in sulfur in gasoline as well as stricter tailpipe emissions standards for cars and light trucks.
"Today's proposal will enable the greatest pollution reductions at the lowest cost," the EPA said in a statement.
The proposed standards will reduce gasoline sulfur levels by more than 60 percent -- down to 10 parts per million (ppm) in 2017, the EPA said.
The Obama administration has said the proposal would result in a one cent per gallon cost increase at the gas pump and would cost about $130 per car in 2025.
But critics say the price to fuel vehicles will be higher, with industry estimates ranging from six to nine cents more per gallon.
"With $4 dollar a gallon gas the norm in many parts of the country, we cannot afford policies that knowingly raise gas prices," said House Energy and Commerce Committee Chairman Fred Upton, a Republican from Michigan.
High sulfur content in gasoline creates more pollutants and adds to smog and soot in the air.
Supporters of the new rules hailed the move as a crucial step in Obama's second term as president, and the equivalent of taking more than 33 million cars off US roads.
"We know of no other air pollution control strategy that can achieve such substantial, cost-effective and immediate emission reductions," said S. William Becker, executive director of the National Association of Clean Air Agencies.
Lawmakers who opposed the release of the proposal, known as Tier 3, said it would raise costs for consumers in an already struggling US economy.
"The EPA continues to disregard the facts and potential economic costs of Tier 3, when consumers and our economy can't afford gas prices going up even further," said Louisiana Republican Senator David Vitter.
"This move signals a frightening flood of new rules," he said.
The proposal now faces a period of public comment before it can be finalized.