Suzuki's Maverick Vinales expects to continue with the 2015 chassis this weekend at Jerez after testing the '16 version again on Friday.

Vinales finished FP2 in the afternoon sixth fastest and eight tenths off the pace set by Jorge Lorenzo, but the young Spanish prospect - in the mix to take over from Lorenzo at Yamaha next season - is confident of making a big improvement on Saturday.

He made one run with the 2016 chassis but feels he will use the older version for the rest of the weekend before experimenting with the update again in Monday's test.

"Not the best Friday but for me we try a lot of things and it was difficult to ride, but anyway I think we did a good job and we tried all that we needed to try, so tomorrow I will try to make an incredible lap," said Vinales, who will also test the wings used by team-mate Aleix Espargaro today during Monday's test.

"I didn't try [wings] but I think I will try on Monday - at the moment we try new chassis and too much things.

"Yes, I did one exit [on 2016 chassis] but at the moment we need time because in Austin, looks like we are better; here, it is difficult to understand," added Vinales, who tested the '16 update during a private test at the Circuit of the Americas.

"I think I will continue with 2015 because I know really well what is the limit with this chassis. Today was difficult to make one good lap time: the pace was not so bad when I exit from the box but then for the fast lap time the set-up was not completely on the good side.

"When we put in the good set-up tomorrow I think we can make a really good lap time."

Vinales said he has not given any more thought to his future after being linked to the vacant factory Yamaha ride because he is too focused on preparing for Sunday's race with Suzuki.

"No - really difficult because I need time to think and here I have too many things: the bike, 2016 /2015 [chassis]. Anyway, this year the result is going to make my decision," he said.

Vinales, meanwhile, revealed he preferred the previous rear tyre available at the start of the season compared to the new harder construction tyre introduced by Michelin following safety concerns.

"For sure I preferred the tyre I had for Valencia in the test, in Australia and Qatar, but anyway it is for everyone," he said.

"[Track conditions were] quite good, compared to last year the lap times were slow but also in Moto3 they were quite slow, but for the moment the track can improve."