James Allison believes Lotus' new E21 is both "competitive" and "reasonably reliable" after a solid first outing at Jerez.
Formula One's pre-season testing kicked off at the Spanish circuit last week where the teams spent four days putting in the miles.
Lotus, who ran their new E21, were the only outfit to finish two days on top with Romain Grosjean setting the pace on Day Two and Kimi Raikkonen was quickest on the final day.
Raikkkonen's time was the second quickest of the week, 0.269s adrift of Felipe Massa's 1:17.879, while Grosjean's best put him fourth overall.
"Winter testing is exceedingly precious," said Allison, Lotus' technical director.
"We get just 12 days to prove out a very complex vehicle. Twelve days to push the car and the team to make sure that we are match fit by the time we get to Melbourne.
"Jerez offers the teams four days of guaranteed good weather on a challenging track that will stress the car from both a reliability and a performance point of view.
"We leave this first test in high spirits having learned that the E21 looks both competitive and reasonably reliable."
Lotus have returned to their Enstone base where the team will prepare for the next test at the Circuit de Catalunya on 19 February
"The main thrust of activity between now and Melbourne is to build up the quantity of stock so that we can go racing," said Allison. "We are using just one chassis here in Jerez, but in a month's time we need to have four tubs ready to go.
"Gearboxes, suspension, bodywork and thousands of small parts all need to be made to allow us to commence the racing campaign.
"At the same time, we will be furiously building a crucial set of Melbourne performance upgrades to allow us to stay competitive. While the factory sweats to get this work completed, the travelling component of the team will plan and execute the remaining two tests.
"They will push the car as hard as they can to make sure we have amplified its strengths and minimised its weaknesses before we have to use it in anger."