The Japanese manufacturer has embarked on a new three-year partnership with Toro Rosso after three disastrous seasons with McLaren.

Over the winter, it overhauled its management structure, moving Yusuke Hasegawa off the F1 project and splitting his role between Toyoharu Tanabe and Yasuaski Asaki.

Its focus has been on improving the reliability, after it had suffered several failures last year.

Honda is hopeful its testing spec engine running at the Barcelona test can provide some improvements ahead of the opener in Australia.

Providing the first specification of the engine delivers as hoped and research and development progresses positively, it hopes to add performance upgrades later in the season.

This year, teams will be limited to just three engines without penalty, meaning they have to last seven races. That means the first major development is likely to be introduced at race eight in France if they stay on schedule.

"Our approach this year is to be first focused on reliability at the beginning of the season," Honda's motorsport chief Masashi Yamamoto told Motorsport.com at Barcelona.

"We have to make sure we have good reliability. That is what we have been working on during the winter season - let's see what happens during winter testing.

"We are still fourth in the pecking order, this year will be the first to ensure the reliability. We will bring some performance improvements during the year.

"First we want to focus on tests one and two. In terms of overall performance, we cannot comment clearly on this as it is only the testing spec for us.

"With performance, there is a bit more to come, and so far we're happy about the reliability but there is still a lot of testing to come."

It is believed Honda's off-season has run smoother at its Sakura and Milton Keynes bases, with potential issues that could have impacted testing found in good time before Barcelona.

Toro Rosso Honda had a successful opening morning at Barcelona, with Brendon Hartley clocking 72 laps. Only Renault's Nico Hulkenberg (73) managed more.