World champion Fernando Alonso says he is excited about the performance of his new Renault car ahead of the first race of the season in Bahrain on Sunday.
"In 2006, I know we have a competitive car in the R26, so my only goal is to repeat the title," the Spaniard said.
"The car is ready to race. It has done a lot of laps, on all types of circuits and conditions. Now is the time to measure ourselves against the others."
Alonso said Honda, Ferrari and McLaren would be Renault's closest rivals.
The 25-year-old said the new car had done well in pre-season testing and that the new V8 engine required by a rule change was impressive from the start.
"We started running on the track quite late with the V8, in mid-January, but we did it with an engine that was already capable of doing race distances," he said.
"It was reliable, with good performance. There have been different philosophies about how to develop the V8 and Renault's has worked well."
Alonso said Michelin has also done a good job in producing competitive tyres in the line with the new regulations introduced for 2006 - tyre changes will be allowed again after they were banned for last year.
Some had expected the change to benefit rival Bridgestone, which supplies Ferrari, Toyota and Williams among the top teams.
But Alonso said: "We are there. We have a super tyre now, it doesn't matter whether the temperatures are high or low. I think we have a good performance and good consistency.
"I am confident that the Michelin will still be the best tyre in F1 this year."
Alonso said he was not worried by the prospect of defending his title.
"I don't think there is more pressure, but I am very proud to have number one on the car," he said.
"It is the maximum you can achieve in motorsport, one of the moments you dream about all your career. I am excited to arrive in Bahrain and I will be trying to enjoy this year to the maximum."
Renault chassis director Bob Bell said both Alonso and team-mate Giancarlo Fisichella were upbeat about both the car and their chances of winning the championship.
And he played down the significance of Renault not joining Honda and Ferrari at a pre-season test in Bahrain.
"The testing Honda were able to do has provided Michelin with good direction on the tyres and that will benefit all the Michelin teams," he said.
"Furthermore, last year we were able to set the car up very quickly and we didn't lose running time optimising set-up. I think the R26 is even better in that area.
"So while the other teams have had the advantage of extra track time, I don't think it will be a crucial factor."