The Spanish former Formula One world champion’s campaign in Florida was derailed by mechanical problems that included two brake failures in his United Autosports Ligier JS P217.
The 36-year-old admitted however he had been unnerved by the experience.
“You’re scared a little bit, no doubt,” Alonso said. “It happened two times in the first corner – you’re right there at 300-310 kilometres an hour then you hit the brakes and there’s no brakes.
“At night, you don’t see clearly the tire wall or the escape road, so there was even a little more of a scare.”
The McLaren driver took to the track in Florida this weekend to gain experience for racing Le Mans.
Alonso has spoken of his desire to take a crack at the “Triple Crown” of motor-racing – winning the Formula One Monaco Grand Prix, the Indianapolis 500 and Le Mans.
Only one other driver — Graham Hill — has successfully achieved that hat-trick. Alonso has two wins in Monaco, and impressed at the Indy500 on his debut last year.
Alonso, who posted the 13th fastest qualifying time in Daytona this weekend, said his experience in Florida would be invaluable when he eventually races in Le Mans.
“It is a positive feeling despite the issues and reliability. It was a very nice experience the whole event,” Alonso said.
“If and when I will be Le Mans, it will be the second time at least,” he added. “So I will be much more prepared for the practice, the race, driver changes, communication, driver preparation between the teams, how much rest you need to have.”
Alonso said last week his chances of racing in Le Mans this year are “50-50”.
McLaren have indicated Alonso will be free to race at Circuit de la Sarthe on June 16-17 should he wish to do so as it does not clash with his F1 commitments.