Rates for the largest oil tankers on their busiest trade route rose for a seventh session to the highest in almost seven weeks on speculation Chinese demand will increase as the driving season starts.

Charter costs for very large crude carriers hauling 2 million barrels on the benchmark voyage to Japan from Saudi Arabia gained 3.5 percent to 36.47 industry-standard Worldscale points, according to the Baltic Exchange, the London-based publisher of freight rates. That’s the highest since March 22, figures showed yesterday.

Chinese imports are expected to grow as the country enters the season when demand for car fuel increases, Sam Margolin, a New York-based analyst at Cowen Securities LLC, said in an e- mailed report today. April crude shipments totaling 23.08 million metric tons rose from a year earlier for the first time in two months, customs figures showed yesterday.

“VLCCs into China continue to improve,” Margolin said in the report.

Daily earnings on the voyage advanced to $4,985, the highest since March 21, according to the exchange. Those assessments don’t reflect owners cutting speeds to save on fuel, their biggest expense. The price of ship fuel, known as bunkers, rose 0.5 percent to $613.36 a ton, according to data compiled by Bloomberg from 25 ports worldwide.

Worldscale points are a percentage of a nominal rate for more than 320,000 specific routes. Flat rates for every voyage, quoted in dollars a ton, are revised annually by the Worldscale Association in London to reflect changing fuel costs, port tariffs and exchange rates.

The Baltic Dirty Tanker Index, a wider measure of oil- shipping costs that includes smaller vessels, fell 0.6 percent to 616. The biggest move in the dirty tanker market was for VLCCs to the U.S. Gulf Coast from the Middle East, rising 7.3 percent to 19.63 Worldscale points, according to the exchange. The biggest change in the market for ships hauling refined fuels was for gasoline tankers to the U.S. East Coast from Europe, gaining 14 percent to 167.92 points.