Mercedes will test a major upgrade package during Magny-Cours F1 test

After a recent spell where it has focused on improving its understanding of tyres rather than delivering updates, Mercedes plans to trial an all-new exhaust system as well as revised double-DRS during this week's Young Driver Test.

AUTOSPORT has learned that as well as continuing the evaluation of the Lotus-style double-DRS that it trialled in Belgium, the Mercedes W03 will feature its version of the Coanda-type exhaust that has been put to such good use by McLaren, Ferrari and Sauber this season.

Mercedes team principal Ross Brawn told AUTOSPORT that the outfit had perhaps neglected car development too much recently.

"We weren't understanding the tyres and concluded that the most effective thing we could do, rather than go straight to a Coanda-system, was to understand the tyres, to get them a bit more under control," he said.

"Perhaps we should have done both in parallel but we concentrated on what we thought was the most important thing.

"We're much better at managing the tyres and we've actually had races where we've made our tyres last better than some of our competitors, which was not the case at the beginning of the year.

"We have also done work in the wind tunnel which, with our new 60 per cent model, has helped us understand more about that type of exhaust system. That's what we'll be evaluating this week."

Brawn said that the Coanda exhaust - which makes use of the tendency of fluid jets to be attracted to nearby surfaces to divert exhaust flow down to the floor - would help the W03 in slow speed corners.

"We think that's quite significant in low speed traction," he said. "The effect of the exhaust is more significant at lower speeds than higher speeds, and also brings you the balance perhaps you need for the rear tyre."

Brawn also said that if tests of its new double-DRS are positive then the plan is to race it as soon as possible.

"There is still a long way to go," he said. "There are some races later in the year where that philosophy might be quite useful.

"It's a passive system - and can only work in certain combinations of corners. With the Ascari chicane at Monza, it was a bit quick to be able to use it there.

"It's about how you use it on track and it's not suitable for all tracks. It has to be tuned and the tuning is a challenge."

The new version of double-DRS allows wings to be stalled at a set speed for a straight-line speed boost.

However, teams need to be able to ensure that the speed it works at is greater than the fastest bend on the track - so downforce is not lost when it is needed most for cornering.

Mercedes test driver Sam Bird is scheduled to drive for the first two days of this week's Magny-Cours test, and could stay for a third day if the programme is not completed.

If the work is ticked off, however, then it is understood that Brendon Hartley could be brought in for a run on Thursday.