Despite signing a contract with McLaren Mercedes worth at least £70 million over five years in January, Lewis Hamilton has barely spent any money since being propelled to worldwide fame as a Formula One driver.

Hamilton, who begins his second season at the Australian Grand Prix in Melbourne this weekend, has bought his parents a new car each and is planning to buy his mother a new house, but that is about as far as his spending plans have gone.

The sport's most successful rookie says he is trying to be sensible with his money. “I haven't spent a penny,” he said. “All I've paid for is my rent. I still have my sponsorship - I am happy driving my Mercedes-Benz [road car] and, clothes-wise, I'm sorted out. I really don't have to spend any money apart from food and rent.”

Hamilton was brought up in Stevenage, Hertfordshire, but this winter he moved to Switzerland, where he enjoys a far less rigorous tax regime than he would at home. The 23-year-old, who finished runner-up to Kimi Raikkonen, of Ferrari, last season, has rented an apartment in the Geneva area.

Property experts familiar with the market say that Hamilton could be paying up to £100,000 a year for a three-bedroomed apartment with views of Lake Geneva and the mountains. Buying a place such as that would cost about £2.5 million.

Hamilton's approach to his newfound wealth is a model of prudence, reflecting the advice he gets from his father, Anthony, who manages his affairs. The McLaren driver laughed, for example, at the suggestion that he might buy himself a private jet. (In fact he has “a really, really good” sponsorship deal with Bombardier, manufacturer of Learjets, which allows him a certain number of free flights in return for appearances as the company's “brand ambassador”.)

His long-term goal is to help his family, much in the way that Michael Owen, the England footballer, has by buying homes for his siblings and his parents. “I honestly think at the moment, it's important I just keep working and doing what I'm doing,” Hamilton said. “In the future, it's all about building a foundation and building that sort of [basis] for my family. I want to be able to take care of my mum.”

Hamilton's mother, Carmen, remarried after separating from his father when Lewis was 2. She is reported to be living in Letchworth, Hertfordshire, and working as a secretary. Hamilton lived with her until he was 10, when he moved in with his father and stepmother.

And Hamilton is already planning for a rainy day. “Even though you get paid more, even though I might have some money now, I don't think it's right for me at the moment to just go out and splash out money here and there because it might all be gone,” he said. “Something might happen to me and I might not have that money. I've got to make sure it's invested properly and make sure we are building a secure future.”

One consequence of his sudden fame is that Hamilton has learnt to trust and value his friends and family more than he might have done had he not become one of the world's most recognisable sportsmen almost overnight. He says he has made no new close friends since he started in Formula One and can count his true friends on the fingers of one hand.

“I've met some really, really nice people, but I just don't go out looking for very good friends,” he said. “I've got friends that have been with me since I was at school, who have stuck with me through thick and thin, and I just regard them as my closest friends. I never feel I need more.”

Another consequence of his meteoric rise has been the loss of his free time. Hamilton says he is far busier now than he was this time last year. There has been less time to train and he hardly sees his new flat because of commitments either with testing and training or making sponsor-related appearances.

“It's been very hard because of the different commitments I have to make right now, juggling it all,” he said. “I haven't seen my family or friends for such a long time.

“I saw my mum for one day recently and I hadn't seen her since Christmas, just because I have not had the time. I get to fly back to Geneva and I am there for maybe one night or a day and then I'm off to a test or an appearance somewhere.”

Anthony Davidson, the Briton, was able to breathe a sigh of relief yesterday after his team, Super Aguri, were finally able to confirm that they will be racing in Formula One this year. The Japanese team have been in dire financial trouble throughout the winter that has forced them to miss several tests and delay confirming either Davidson or Takuma Sato, his team-mate, as competitors. After last-ditch talks in Tokyo, however, the team have been acquired by the Magma Group and their cars and back-up equipment have been flown to Melbourne in time for this weekend’s Australian Grand Prix.