Maverick Vinales and Aprilia made it five different MotoGP manufacturers in the top five on the final day of official 2021 track action, at Jerez.

But while rival factories face a race against time to select their engine designs for next season, it's less critical at Aprilia, which remains free to develop throughout 2022 as part of the technical Concessions package.

With that in mind, while test rider Lorenzo Savadori evaluated a series of new aerodynamics, with a revised exhaust and chassis also on show, Vinales' main priority was to work with the electronics to improve his braking.

"We didn't try anything specific, we just tried to improve the feeling, especially on braking. It's been an area where I struggle a lot, especially in races," Vinales explained.

"But here we made a big improvement with the bike, with the electronics, and at the end the objective of the test is done. So we are quite happy and quite pleased with how the bike was working, especially on the brakes."

Pressed to explain the braking issues he was having, the former factory Yamaha rider replied:

"I was used to a bike with a different way of braking, so I just need to readapt and the guys gave me a hand especially about engine brake, to make the bike more smooth on entry and to be more comfortable.

"So that's what we worked on here: More stability, more comfortable and I can brake much later. So fantastic."

Nonetheless, Vinales made clear he needs "much more things, more laps, more tests" before the RS-GP starts to feel like 'his' bike.

The next big date is the end of January and the opening test of 2022 at Sepang in Malaysia, where improving the turning will be top of Vinales' priority list.

"Turning is the area where we need to improve. So we need to wait until Sepang to keep trying, but it's nice that we have a clear direction.  I'm very pleased about the test."

The Spaniard, who finished in a best of eighth place in his five end-of-season Aprilia appearances, added:

"We need to wait until Sepang [to know what to expect next year]. I feel a lot of potential on the bike, but still we can't take it out. So step-by-step.

"Now we have a lot of information, the factory has time to work, and then at Sepang sure we will have new things, new chassis, new stuff which is going to make everything much more easy on the riding side."

As well as the opportunity to continue engine development throughout the season, the Concessions mean that Vinales and team-mate Aleix Espargaro will again be the only MotoGP race riders allowed to take part in private testing.

"We're going to try to use all the days we can," Vinales said. "The only problem is sometimes the bikes are very far away, for example if they are in Qatar. But we want to try to do the maximum we can.

"It's very important for us to improve the bike. Every step we do, even if it's a little step it's going to make a lot of difference during the season. And for sure I will visit the factory, I will explain the feeling about the tests, about everything. I can't wait to improve and to work."

Francesco Bagnaia (Ducati), Fabio Quartararo (Yamaha), Alex Rins (Suzuki) and Pol Espargaro (Honda) were the four riders ahead of Vinales on the final day, when the top KTM rider was Brad Binder in eleventh.

Espargaro - who gave the RS-GP its first podium at Silverstone this year, on the way to eighth in the world championship - was 16th quickest on the final day of testing.