The Environmental Protection Agency will unveil draft low-sulfur gasoline and vehicle emissions rules Friday, according to a news report and a source familiar with the plan.

Public health advocates have long pressed for the so-called Tier 3 standards, which have faced major delays, while refining industry groups say they will impose major and unnecessary costs.

The Washington Post, citing sources briefed on the topic, reports EPA would roll out the proposed rules to cut the sulfur content of gasoline by two-thirds and set tougher vehicle pollution standards by 2017.

A source familiar with the rule confirmed to The Hill that it’s expected to be unveiled Friday.