Gov. Ned Lamont wants to save drivers money by lowering the cap on Connecticut's unpopular car tax, but his plan is already hitting a potential road block.

The governor hit the road to pitch his plan in South Windsor on Friday.

"I think the car tax is merciless," he said. "The same car in Bridgeport, you're paying five times more on it than you are in another town with a much lower mill rate."

Lamont's proposal would lower the maximum property tax on vehicles to 29 mills, down from the current 45 mill cap. A mill is equal to $1 of tax for every $1,000 of assessed value. So if your vehicle is assessed at $30,000, you'd pay no more than $870 in car taxes under the lower cap.

"I hope that makes a difference. That's something that will kick in, assuming we get this through the Legislature, on July 1," said Lamont.

But the governor's plan could be in trouble. At a hearing Friday, the co-chair of Connecticut's budget committee declared Lamont's idea dead on arrival.

"I philosophically disagree with this policy," said state Sen. Cathy Osten (D-Sprague).

Osten says only wealthy car owners would see real savings under the governor's proposal.

"It actually does not provide savings in the area where I think where that savings should be, and that's on the lowest people paying taxes," she said.

Lamont's proposal reimburses local communities for lost car tax revenue, but cities like Bridgeport are worried they'll be left holding the bag if state finances turn lean.

"I will tell you from experience that, that does not always work out that way in the numbers," said Bridgeport City Finance Director Ken Flatto.

Lamont countered, "What we've done is, scheduled this in a way, I think we'll be able to give people strong guarantees, we're standing by that 29 mill rate."

In an election year like this one, drivers are likely to get some car tax relief. But the question remains how much and who will benefit the most.

The legislature's Appropriations Committee will vote on Lamont's plan in the coming weeks.