Red Bull unveiled the RB9 at their Milton Keynes factory on Sunday.
"It's a tribute to all the hard work of the guys over the winter because we had a very tight championship battle last year," said Newey.
"It was difficult trying to continue development of last year’s car while also doing research into the RB9. Obviously it worked for us, but it gave us a very tight timeframe to design and manufacture this car."
"RB9 is an evolutionary car," he added. "Probably the most significant change is not the regulations, but the new Pirelli tyres. We had a quick test with those in practice ahead of the Brazilian Grand Prix but in truth we didn’t learn a lot because of the conditions. Pirelli have supplied us data about how the new tyres behave but past experience tells us that it’s only when we go testing that we really find out."