Sonoma and Marin rail planners on Tuesday were favoring an American-style, heavy rail car over the lighter European versions to run on the 71-mile Cloverdale-to-Larkspur line.

The final decision is expected when the Sonoma Marin Area Rail Transit board meets Wednesday, capping eight months of study and debate.

?It is passionate because this is one of the biggest decisions we will make and it will impact the people who ride it,? said Debora Fudge, a Windsor councilwoman and vice chairman of the SMART board. ?They will see these cars, and they will look sleek and modern.?

The SMART staff is recommending purchasing the American-style cars because they will pass Federal Railroad Administration crash criteria, can be run at the same time as freight trains, and meet Federal Transit Administration?s Buy America requirements.

If the European vehicles were chosen, it would require seeking federal waivers that could delay the planned 2014 start-up.

The American-style cars are not as fuel efficient as the lighter European vehicles, but have more seats and provide equal savings of greenhouse gas emissions, and could be electrified in the future, according to the SMART staff.

?The majority understand it?s a tough choice, but in the end the regulatory environment is what it is, and we don?t want to have a system based on regulations that we wished existed. We need to build a system based on regulations the way they are,? said SMART spokesman Chris Coursey.

SMART is asking the 12-member board Wednesday to write specifications to build a fleet of 11 American-style cars, at a projected cost of $88 million.

The board has debated the choice since December and many had clung to supporting the European-style cars, even though only one manufacturer indicated any interest in possibly building them to U.S. emission standards.

?All of us are agonized over this decision,? said Charles McGlashan, a Marin supervisor and chair of the SMART board.

McGlashan said he was leaning now toward the American-style cars, given the assurance that the ride could be equal to that of the San Diego light-rail car a SMART committee rode.

?I was strongly of a mind at that point the light would be the way to go,? McGlashan said. ?But first of all no one wants to build it except for one manufacturer, and that means he would have us over a barrel. And Buy America is a good public policy and walking away from that and asking for waivers is not trivial.?

He expects the board to approve the American-style cars, but doesn?t think it will be unanimous.

Fudge was another European-vehicle advocate who said she is now leaning toward the American-style vehicles, but wants to be sure they are better than those already in use elsewhere.

?I want to see them way more efficient, way more comfortable and way more quiet than the rail cars that have been on the line for the last 10 years,? Fudge said.

Mike Kerns, a Sonoma County supervisor, said he too had hoped for the lighter cars, but the drawbacks are too great.

?It really comes down to not light versus heavy, it comes down to compliant to non-compliant vehicles,? Kerns said. ?I?m confident we could have the heavier car, the compliant vehicle, that will meet all of our needs and wants for this project. If we go elsewhere, it?s a risk.?