Manor Racing hailed the MRT05 as by far the best Formula 1 car it has produced as it unveiled the new, Mercedes-powered, design on the first morning of Barcelona testing.
F1's smallest team's deal to use Mercedes engines and Williams transmission and other components is expected to bring it much closer to competitiveness after six seasons adrift of the midfield pack.
Pascal Wehrlein left the garage in the MRT05 just under 90 minutes into the first day of the test.
Manor technical director John McQuilliam said the team was confident of a massive step forward in 2016.
"Even at this early stage of the game, we can easily say this is the best car we've ever launched," he said.
"Certainly the most developed, the most ambitious and the most aggressive.
"The overall package is a very significant step forward, not just from last year, but from any of the cars from our stable.
"Yes, we have a long way to go from here in terms of developing the MRT05, but it's already a dream package for the 154 Manor Racing people who've worked so hard to design and build it."
Manor's new racing director Dave Ryan, who arrived after the exits of founders John Booth and Graeme Lowdon last year, said he had been impressed by what he had seen at the team so far.
"It's been a very busy time, but it has really served to underline everything I thought when I first agreed to join the team - a great little operation, with huge potential and the vision and ambition to make a big step forward," Ryan said.
"The team did a laudable job last year given its circumstances over the previous winter.
"This year, with the package we have, we need to be every inch the professional racing outfit."
Manor only just made it to the start of the 2015 campaign after being rescued from administration on the eve of the season, and used a modified '14 car for the year.
It has an all-rookie driver line-up in DTM champion Wehrlein and GP2 race winner Rio Haryanto.