A total of 57,224 voted in favor of the tax measure, and 57,027 were opposed, or 50.09 percent to 49.91 percent.
The tax passed despite donations of $243,500 by rental car companies, and spending by opponents of $270,677, including $33,500 on polling and $72,190 on TV advertising.
The Elections Office would undertake a recount only if someone requested it within a five-day window after the election is certified, Elections Manager David Tom said in an interview. Certification must take place within 28 days of the complete and final count of all ballots.
There is no threshold below which a recount becomes automatic. "We've had contests that are much closer than (197 votes)," Mr. Tom said.
Measure T imposes a 2.5 percent tax on the gross receipts of vehicle rental companies in unincorporated parts of the county, including San Francisco International Airport. The companies would be expected to pass the tax on to customers, mostly visitors.
Measure T was one of three deficit-reducing measures the Board of Supervisors proposed for the coming fiscal year, which starts July 1. The measure is expected to raise about $7.75 million and lower the county's projected deficit to $33 million for the fiscal year.
Voters defeated the other two measures — U and X — that would have added another $5.2 million a year to the county's annual revenues. Each failed with about 53 percent casting "no" votes.
To cover the deficit and balance the $1.83 billion spending plan for the 2012-13 fiscal year, the county will draw down its reserves to about $160 million, Budget Director Jim Saco told the Almanac.
Measure U would have raised the hotel and motel occupancy tax rate in unincorporated parts of the county to 12 percent from its current 10 percent, raising about $200,000 a year.
Measure X would have raised an estimated $5 million by imposing an 8 percent tax on commercial parking facilities located in unincorporated parts of the county, including SFO.
Opponents to the tax measures organized as a committee with the name: "No on T, X and U, Taxpayers for a Strong Economy, Sponsored by the Local Tourism Industry."
Campaign finance forms show two donors: Enterprise Rent-A-Car Company of San Francisco, which gave $218,500, and Hertz Corporation, which gave $25,000.
A late filing shows another $155,000 loan from the committee itself, and Enterprise gave $10,000 in in-kind contributions in legal services.
The committee spent a total of $270,677, including $33,500 for polling, $26,933 for professional services, $22,500 for campaign consulting, and $72,190 on TV advertising, the reports show.