The team is happy with where they are at with the new E23.
Lotus technical director Nick Chester has rated the Jerez test as very positive for his team despite missing the first day of running.
Lotus started its 2015 pre-season one day later than its rivals as the new Mercedes-powered E23 did not arrive in time for the opening day of work at the Spanish track.
The objective was to have a car that was easier to work with than last year's and it is.
Lotus' Nick Chester
Despite that, the Enstone-based outfit enjoyed a productive test and Chester says the progress was encouraging.
"Overall, very good," Chester said of the test. "Obviously we missed the first day's running and had a big push to ensure that we could get running on the second day which was actually earlier than we expected.
Good out of the box
"Straight away the car was good out of the box, very reliable. We found working with HPP has been brilliant, it's a very easy relationship. The performance is coming along nicely too. It's been a very good test for us."
He added: "The objective was to get some mileage and flush out some of the major problems we might encounter so that we could go to Barcelona knowing that we had a reliable car.
"We've definitely done that and more. We've been able to do a little bit of set up work and start understanding the car."
A massive step forward
Chester confirmed the view from drivers Romain Grosjean and Pastor Maldonado that the new car is a massive step forward compared to its predecessor.
"They [the drivers] find it massively easier. The objective was to have a car that was easier to work with than last year's and it is.
"It's like night and day so far."
"They're very positive, they both find the car a lot more consistent to drive, they love the power unit which is very flexible for them and the whole package is much easier for them to drive and put on the limit."
Chester said Lotus will have new aero parts for the first test at Barcelona, and revealed the third E23 chassis had been built and homologated.