Gone are the 2.4 V8 engines of last season. All cars must be powered by 1.6 litre V6 turbocharged engines, a variety last seen in Formula One in 1988. The cars now carry an energy-recovery system that harvests the heat of the exhaust gases and the stopping-force of the brakes to produce a significant boost of power for over 30 seconds a lap, useful to overtake or keep from being overtaken. The tyres still need to be nurtured or they will lose their performance, and the fuel allocation has been cut from about 160kg to 100kg, so the engines must run lean to reach the finish.
Three engine manufacturers are supplying the whole field of 22 cars: Mercedes (Mercedes team, McLaren, Willams, Force India), Ferrari (Ferrari team, Sauber, Marussia) and Renault (Red Bull, Toro Rosso, Lotus, Caterham).
Preseason testing showed all teams experiencing teething trouble with the new systems but some had major problems with cars repeatedly breaking down and losing valuable testing time.
A revitalized Williams team is now Williams Martini Racing, and sporting the go-faster stripes of its new sponsor.
Last season was one for the team to forget, scoring just five points and ninth position out of 11 teams.
Now they have 11 times race winner Felipe Massa, fresh from Ferrari, and he is pleased he decided to sign for Williams instead of some of the other teams he had considered.
"The possibilities I have, going to Lotus or maybe to Force India, or maybe even McLaren which was a very small chance. But I think I did right, I made the best move, you know," the Brazilian said. "I think it was the right time. You know I miss so much to get back competitive. Williams is missing so much to get back to the, you know, top level."
Testing saw Williams as one of the fastest and most reliable with a Mercedes engine and a car that appears to run consistently. Finland's driver Valtteri Bottas is starting his second season after proving quick in his rookie year.
Red Bull Racing has four-time and current world champion Sebastian Vettel being joined by former Toro Rosso driver Daniel Ricciardo of Australia. The team's testing difficulties seemed at first to centre on their Renault engine which performed fine at the Renault factory but not in the Red Bull car.
However other teams, notably Caterham and Toro Rosso, overcame problems with the Renault engine and its cooling, and delivered some long reliable runs. Red Bull's problems persisted with Vettel just completing one lap on the penultimate day of tests. But Red Bull have started a season with problems in the past and then developed the car back into points contention later in the season. The 2014 season may be no different.
Tony Fernandes, the Malaysian owner of the Caterham team, says he hopes the 2014 season will see them score their first points. First as Lotus Racing and thenCaterham, the team is entering its fifth season without finishing tenth or better. Scoring one or more points brings a sizeable financial bonus which can boost a team into the midfield.
Japanese driver Kamui Kobayashi comes to Caterham courtesy of his Japanese fans who have raised enough cash for him to buy into the team - he is driving for free. He was dropped by Sauber for 2013 and has had to sit out a season.
Kobayashi is joined by Sweden's Marcus Ericsson, following in the tradition of the much-loved Swedish driver Ronnie Peterson who twice came second in the world championship in the 1970s before his death.
The Sauber team's testing experience illustrates the uncertainty before the start of the season.
McLaren's chief executive Ron Dennis returns to take control of the Formula One operation, aiming to improve the fortunes of a team that finished fifth in the 2013 world championship, their worst result since being excluded for breaking the rules in 2007.
The 2014 season comprises 19 races with teams expecting significant improvement in performance and reliability after the early "fly-away" races.