Valentino Rossi came within 15-minutes of leading the opening day of official 2018 MotoGP testing at Sepang, as Yamaha's back-to-the-future chassis strategy made an instant impact.

After last year's low-grip woes, the team has reverted to a frame based on the more user-friendly 2016-design.

Riding in both the wet morning and scorching afternoon sun, Rossi topped the test on several occasions - and the #46 machine was still heading the timesheets when he packed-up at 5:10pm.

However, Rossi had been pushed down to fifth by the time he spoke to the trackside media and finally sixth place (+0.806s), but still top Yamaha, when the action officially ended at 6pm.

This is what the nine-time world champion had to say about his day, the bike and future in MotoGP…

Q: Everything looks positive today, were there any negatives?

Valentino Rossi: That it's just the first day and this is MotoGP; so you stop and you lose 3-4 positions! But like I said it's just the first day, so it's nothing, but we start well. I don't remember one day like this last year. I was always complaining.

I'm happy because in November we did a good job, we understand better after the confusion during the season and the chassis of today is a new chassis, an evolution, but based on the 2016. So when I ride this chassis I feel better. My riding is normal. I feel better in the front and when I push I have good speed.

And after we concentrate also in other areas because we try two different engines to improve the acceleration and are not so bad. Also the top speed is quite good. And especially on the electronic, because on the electronic we need to work especially to save the rear tyre.

But the first impression is positive.

Q: You say you were working to save rear tyre, did you do any longer runs and see an improvement?

Valentino Rossi: I don't do long runs because I think, like a lot of riders, the first day here in Malaysia after the winter is a disaster! Physically it's very strong. Also you try to save some energy also for tomorrow and the next day. Because if you push too much today after become difficult.

But anyway I finish the race distance with the tyres, if not with [one long run]. And I have a good lap time after 20 laps. So the first impression is we have to work, because we are still not very precise, but the idea is good.

Q: Now everyone has a counter-rotating engine, Yamaha has lost one of its advantages?

Valentino Rossi: It was always something of a Yamaha bike. Now everybody has it. But I think our bike is good not just because of that. There are a lot of other things that work well. It's normal that after some years everybody understands the right ideas and make the same. But the feeling is good.

Q: You say that the chassis is based on the 2016 chassis, is it the same as you tried here in November or slightly different?

Valentino Rossi: Slightly different. In November we understand what I like of the 2016. It was a good test because we were alone, we can make a lot of back-to-back tests and sincerely my idea was already clear before the test. But in the test also the Japanese understand and I'm very happy that the base of the bike starts from the 2016. Because this bike is better to ride, for me.

Q: Did you feel relieved today that it felt like the 2016 again?

Valentino Rossi: Yes. Because this morning [in the wet] was not so bad already, but nothing special. Also because I had the soft tyre and not a lot of water. But in the dry, already from the first exit I was able to go in 2m 0.7s and from that moment I was always strong. This is very important.

Q: At the moment, four of the top five riders - Pedrosa, Dovizioso, Crutchlow and Rossi - are four of the oldest riders in MotoGP. So why would you stop racing?

Valentino Rossi: I think that depends very much rider by rider. But I have motivation. I want to try to continue. For me the experience is important for sure and physically you pay something, but at the end the physical condition is not the most important thing.

Q: After today's performance maybe you can sign for Yamaha tonight?

Valentino Rossi: I said that I want to wait until after all the tests because first of all I want to understand if I am competitive, if the bike if competitive. And also it's the worst moment of the season because, so if I have enough power to make the tests, I will re-sign [laughs]!