Jorge Lorenzo looked back to the kind of form that took him to four straight wins during the opening day of the Indianapolis MotoGP.

The Movistar Yamaha rider narrowly held off Honda's Marc Marquez to lead both Friday practice sessions.

But the #99 set his best lap time with used, hard compound tyres both front and rear. The Spaniard feels that fitting a new set of rubber alone would give an instant improvement of at least 0.5s.

Related Articles

Lorenzo is fighting to close a 13-point championship gap to team-mate and title leader Valentino Rossi, with the Italian was only tenth quickest on day one.

"Very good, very positive and very happy with the start to the weekend," began Lorenzo. "After a lot of days without riding it is very important to feel fast and comfortable on the bike and that's how I feel today.

"We had the same sensation with the harder tyre, while other riders had used a new soft tyre they couldn't even get close to our time, so that was a very good sign.

"We still have one-second or so of margin to the lap record, so I think with a new tyre - because we didn't put a new tyre at the end like some riders - we have probably half a second or more and we can improve the bike to get close to the lap record or even better."

Lorenzo has made clear that a change in tyre allocation, or more precisely the absence of a special edge-grip treatment, was a significant factor in seeing his four-race win streak followed by tougher events at Assen and Sachsenring.

While the medium rear tyre compound is again without the edge grip treatment at Indianapolis, it is present on the hard compound. That, combined with the high-grip nature of the new-for-2014 Indianapolis asphalt, means Lorenzo has so far avoided the wheel-spin issues that taunted him in the last two rounds.

"Assen and Germany were hard for me. After some laps the tyre started spinning too much in acceleration and I couldn't take profit from my riding style," he confirmed.

"I don't know why but this tarmac, for the last two years, is quite grippy and constant and even if the tyre is the same as Germany and Assen I don't feel so much difference between this tyre and the one I used for the four victories.

"I think here I can fight for the victory. For sure the podium is a good result, but if it is possible to win we have to try."

Next weekend's Brno round will then see the return of Lorenzo's favoured medium-compound with edge grip tyre combination.

"For sure in Brno, with the [tyre] edge part a little bit softer like before, like a normal tyre, we can be maybe a little more competitive."

But with Marquez back on form, Lorenzo played down his chances of another four-in-a-row romp.

"Very difficult because Marquez is again in shape with the old chassis and for sure he will try to recover all the points [he has lost], risking a lot and going very fast. We have to try to win when we can and when we cannot try to finish the race."

Meanwhile the Mallorcan won't be surprised to see Rossi turn around a slow start to the Indianapolis weekend and be fighting at the front on Sunday.

"It's still only Friday. Valentino normally improves a lot during the weekend and especially on Sunday he is always competitive. For sure he will be there," Lorenzo declared.