The Senate Finance Committee last night decisively approved a 5-cent-a-gallon increase in the federal gasoline tax and a major jump in the taxes on heavy trucks to pay for the administration's highway, bridge and mass transit repair program.

The committee, by a 15-to-4 vote, thus joined the full House in supporting the increase from 4 to 9 cents a gallon on gasoline and diesel fuel, and set the same effective date, next April 1.

However, the committee's tax package on trucks is weighted more toward lighter vehicles than the House version and reimposes taxes on tires and retreads for automobiles that the House had repealed. The House version was more in line with the administration proposal, which sought to allocate highway taxes in proportion to the amount of wear and tear done by various vehicles.

Transportation Secretary Drew Lewis said last night that the important thing was "to move the bill," and that the final result would be determined in conference.

Ross C. Gaussoin, chairman of the board of the American Trucking Associations, called the committee measure "a shock" and said, "We expected much more of a compromise."

The bill now moves to the Senate floor where a filibuster has been promised by Sen. Gordon Humphrey (R-N.H.). The bill also faces opposition from groups ranging from environmentalists seeking to block further interstate highway construction to road-building groups opposed to expanded Davis-Bacon wage protections.

Nonetheless, Finance Committee Chairman Sen. Bob Dole (R-Kan.) predicted the measure will pass, but said, "It's going to take a while."

The tax package is part of a complex bill that would raise about $5.5 billion a year in new highway money to be apportioned among the states. Democrats are supporting this as an antirecession measure that will produce jobs; Republicans are supporting it less as a jobs bill and more as way to meet obvious transportation needs.

As was the case when the tax increase passed the House Ways and Means Committee last week, most of the Finance Committee discussion was devoted to resolving problems for special interests.

The panel exempted farmers, state and local governments and all buses, whether publicly or privately owned, from paying fuel taxes, exemptions that have long been in place for the existing 4-cent-a-gallon tax. Taxicabs were granted a 4-cent exemption.

Then, clearly in deference to grain-state Chairman Dole, they exempted gasohol from the 9-cent-a-gallon tax. The House had left gasohol with just a 4-cent exemption.

The inclusion of 1 cent of gasoline tax revenue for transit was attacked by Sen. Steve Symms (R-Idaho), but his motion to remove transit systems as recipients of the tax revenue failed, 14 to 4.

The truckers, meanwhile, lost a round yesterday in the Senate Environment and Public Works Committee, which completed its action on the highway portion of the bill by denying truckers the right to seek state permits to use 105,000-pound, triple-trailer rigs on interstate highways nationwide.