Drivers were paying the equivalent of about $7.32 per gallon of diesel yesterday. By contrast, diesel was selling in the United States for about $4.75.
Truckers also blocked a number of roads around the country, including some leading into the center of Barcelona and the international border with France.
"We are the ones who move the goods that this country needs to keep working. If we stop because we haven't got the money to buy fuel then the country will stop," Julio Villascusa, president of Fenadismer, the transport association , told Cadena SER radio.
Fenadismer representatives and Development Ministry officials met yesterday but failed to reach agreement, stretching the strike to a second day.
Fenadismer said more than 90,000 drivers have been called to take part in the strike.
The strike was not expected to have a major effect on city food markets until later in the week.
There was almost no movement of trucks early yesterday at Mercamadrid, the main wholesale food market for the Spanish capital.
Development Ministry transport chief Juan Miguel Sanchez said the government will guarantee market supplies.
A strike by fishermen across Spain also protesting fuel costs has entered a second week. News reports said smaller boats that fish closer to the coast have joined the protest, which began May 30.
The stoppages are part of protests across Europe against rising prices.
