Lotus technical director Nick Chester is confident that the team has made a big step with the E23, and not just as a result of the timely switch from Renault to Mercedes power.
Chester says that the chassis is much improved, and compliments the stronger power unit.
"This year is looking a lot better, the power unit is a big step forward," said Chester. "The chassis is also a step forward, the drivers can get a lot more from it and it's easier to drive on the limit, as well as being more predictable.
"We spent some of the test exploring the E23's suspension geometry and it has a lot of effect on the balance of the car in the middle of the slow speed corners. We're also making the car less sensitive for the drivers so it's easier to extract performance.
"The power unit has strong performance and response and it's extremely reliable, we've only used one unit throughout testing. Its installation is nice which gives us some benefits, such as the way we've organised our cooling system."
Engine switch a challenge
Chester admitted that there had been some challenges associated with the change of supplier, especially related to cooling and installation: "The response of the power unit in addition to peak power does play a significant role and we have found that tuning our control systems has been made easier with a very responsive power unit.
"I don't think our approach changes as we're always aiming to make the car better. The area where we didn't take too many risks was the engine installation.
"We wanted to be reasonably comfortable with cooling and we've been quite conservative ahead of Melbourne. The rest of the car is our usual approach, pushing the boundaries as we try to keep finding improvements.
"It's been a challenge to fit the engine as the rear surface of the chassis is quite different and we had to do a lot of work to have a neat installation.
"We've gone back to air to air charge air cooling because the packaging switch to Mercedes power on a short timeline meant we had to find a simple solution."
More updates in the pipeline
Chester says that the E23 has already been significantly upgraded, and that bigger updates are coming for Malaysia and China.
"It has changed, there's been some updates throughout testing and some more minor ones are on the way for Melbourne, with the bigger upgrades planned for rounds two and three.
"We have a normal programme through the race weekend, it won't be particularly conservative and will be about maximising the car.
"We take a view based on risk for fitting development parts, sometimes there is minimal risk for extra performance so parts can be introduced immediately.
"Sometimes there can be a downside and you need to accumulate mileage for a few practice sessions before fitting for qualifying and the race."