It has been a bittersweet Formula One season for Indonesian race driver Rio Haryanto, not unlike the cup of kopi-o kosong - coffee without milk and sugar - that he orders as expertly as any Singaporean.

The 23-year-old, who spent his teenage years honing his karting skills here, had hoped to be able to race in the Singapore Airlines Singapore Grand Prix in his rookie season with Manor.

With strong financial backing from the Indonesian government, he was Indonesia's first-ever F1 driver and the only Asian on the starting grid this year.

However, after 12 races, his pool of funds dried up, and he was demoted to a reserve driver as Esteban Ocon took over his racing spot last month.

Of the premature end to his season, he told The Sunday Times: "It's such a shame that I cannot race here. I felt down and sad, especially because I know that the Singapore race is the closest to a home race for me.

"But F1 is a business and it is understandable why I cannot finish the season."

The agony of losing his seat was keenly felt, especially this weekend, for he feels right at home in the Republic.

His family owns an apartment on Amber Road, where his paternal grandmother lives, and his face lights up when talking about his favourite food - Wee Nam Kee chicken rice.

"If I race here, I'm sure that there will be a lot of Indonesians who will come and support me," said the boyish-looking driver, who was stopped several times by fans for photos at Marina Square.

Haryanto had to deal with the weight of expectation from his adoring countrymen, who expect him to achieve the same level of success as he did in last year's GP2 series, where he posted three race victories.

Racing in F1 this year, his best finish was 15th at Monaco in May and he completed nine of his 12 races.

He said: "A lot of people expect that I can win races, but F1 is very different and a huge jump from GP2.

"The races are longer and there's more communication with the engineers. It is more complex. We have to strategise for every race, on how to stay ahead of our closest rivals Sauber."

He noted that his team, Manor Racing, F1's smallest, "has a huge influence" on his performance.

"I hope that people can be a bit more patient. I was struggling. You want to have good results, but it's not easy when you are competing with a team that is at the bottom of the field."

Ironically, because of the demotion and loss of his race seat, new sponsors have now stepped forward to support him. And Haryanto is optimistic that he will raise the sum of money, amounting to more than £10 million (S$17.7 million) to return to the starting grid next year.

"I have not thought about the possibility of racing in other series," he said. "I think I have proven my capabilities as a quick driver. I am confident that I will be back in F1."