Thursday 14 August at 11:22 : Scott Speed this week declared himself happy with his abortive formula one career.

The 25-year-old failed to score a point in his 28 grands prix for Toro Rosso, before he fell out spectacularly with the team's management last year and was replaced mid-season by Sebastian Vettel.

Still with Red Bull backing, Speed moved on to the lower tiers of American stock car racing, and his impressive run to date indicates he may soon graduate to the premier NASCAR ranks.

He looks back on his time on the F1 grid with fondness.

"Formula one was always my dream, always way above NASCAR," Speed is quoted as saying by USA Today.

"In my mind, I have accomplished what I'm going to in my life," he added.

Speed said he views simply reaching formula one as his real achievement, and now trying to conquer NASCAR as a bonus.

"I did absolutely nothing in F1, but I'm 1000 per cent satisfied," he explained. "It's like going to college of the world.

"I never went to college, but I know a lot because I had the opportunity to live in Europe and travel the world."

Speed was regarded by some seasoned F1 observers as uncouth, so he smiles at his new image among the stock car community.

"Now I get to come back and I'm the cultured one. There is a lot of money in NASCAR, but everyone is still pretty simple," he said.