Lotus have become the first Formula 1 team to unveil their new 2013 car.
Team principal Eric Boullier said Lotus have set a minimum target of third in the constructors' championship, one place better than 2012.
Technical director James Allison said: "The detail (changes) add up to a significant amount of performance."
There were no obvious innovations on the car at launch but teams usually keep these under wraps until closer to the first race, which is in Australia on 17 March.
"The rules for 2013 are very, very similar to those for 2012," Allison said. "So you can expect a lot of family resemblance from the 2012 car, but as ever in F1 the devil is in the detail.
"There are some neat new ideas and some pushing of the same sort of concepts we have been working on for the last few years."
One of the few rule changes this year has been that teams are allowed to use what has become known as a "vanity panel" to disguise the ugly steps on the top of the noses that drew criticism last year.
But the new E21 did feature a step on the nose in the area of the front tyres, although it is more elegantly implemented than many in 2012.
Allison said: "We have not done it yet because the cosmetic panel would weigh a few grams and with a Formula 1 car putting a few grams on that you don't need to is anathema.
"But if we find a cosmetic panel that looks nice but much more importantly and crucially gains us a bit of downforce we'll pop it on quick as you like."
One obvious change from the 2012 car was a new design for using the exhausts for aerodynamic effect. The bodywork that helps guide the exhaust gases down to the area where the rear floor meets the rear wheels - where the gases 'seal' the gap and create downforce - is reminiscent of that on the 2012 championship-winning Red Bull.
Raikkonen, who was one of the stars of last season on his return to F1 after two years in rallying said: "It's not going to be easy to improve what we did already last year but that is the aim. Hopefully we can do it."
He added that he expected the same teams to be competing at the front. "I don't think the running order will change a lot," Raikkonen said.
Team-mate Romain Grosjean came in for heavy criticism last year as a result of a series of first-lap accidents, one of which resulted in a one-race ban.
He said: "It's clear we had good qualifying speed and too many incidents. And that is what we are going to try to work on."
Lotus also named last year's GP2 champion Davide Valsecchi of Italy as their third driver with Belgian Jerome D'Ambrosio remaining the official reserve driver.