"This is utterly ridiculous. I wouldn't mind if this was just a one-off event, but these petrol shortages are happening more and more often," Capapinha said. "It seems so absurd when we're producing so much oil."
Angola is sub-Saharan Africa's second biggest crude producer, with a current yield of than a million barrels a day, but it seems that not nearly enough petrol or diesel is reaching the capital to satisfy demand.
On this occasion, a problem with the assembly of storage containers was said to be behind the shortages. Last time, technical glitches at Luanda's decrepit and low-capacity refinery were blamed.
Poor roads hampering supply, a lack of warehouse space and a rapid increase in consumer demand have all at one time been put forward as excuses.
"The roads are incredibly bad and there is so much traffic that we have difficulties accessing the port," said Miguel Mendonca, a spokesman for Sonangol Distribuidora, the distribution wing of state-owned Sonangol.
"Then there's the simple fact that the number of cars has risen dramatically in recent years and we simply don't have enough service stations to cope. This invariably leads to shortages and delays," he told Reuters.
Luanda's traffic is hectic at the best of times, but when petrol queues merge into the melee of normal congestion, tempers fray more easily.
One expatriate, whose husband works for a big foreign oil company, said her experience of trying to fill up her tank had reduced her to tears.
"I was waiting in a queue for more than an hour, being beeped at by taxi drivers and hassled constantly by street sellers, only to get to the front and discover that they'd run out of diesel," she said.
"At this point, I burst into tears, had to reverse out of the garage and scraped my car against another van. It was just a total nightmare."
Fuel-hungry drivers - many queuing long into the night to try to beat the crowds - grew increasingly tense as their gauges approached empty. Some left it too late and were forced to push their cars onto the forecourt.
Angola's population of 13 million is expanding rapidly and there are an increasing number of vehicles on the road.
Mendonca said that more than 75,000 second-hand cars had arrived in the capital in recent months, fuel consumption in Luanda had doubled since 2003, and demand in the interior of the country was also steadily increasing.
Sonangol was well aware that distribution capacity needed to be drastically increased.
"Sonangol is going to invest more in service stations. We have a plan to build around eight new service stations in the capital this year, as well as refurbishing existing petrol pumps," Mendonca said.
Moves are also afoot to build a bigger refinery as the existing facility in Luanda - run by Total - is prone to maintenance problems and stoppages which force Angola to import many refined products.
But plans for the $3.75 billion, 200,000 barrel-per-day Sonaref refinery in the port city of Lobito have hit snags with sources saying Sonangol is struggling to find partners willing to give it their financial backing.
"The refinery has been talked about since 1997 or 1998 but it's not got going yet," said one industry expert. "Clearly it would help, but even if the project got the green light this year, it would probably take another four years before it started producing.
"No one will hold their breath waiting for the Lobito refinery, and even if it does get off the ground, there will still be the distribution problem."