Pol Espargaro says he "almost couldn't follow" KTM test rider Mika Kallio during Friday's MotoGP practice sessions at Jerez, as the Finn was testing a prototype RC16 for 2019.
The prototype bike for the 2019 MotoGP season was first debuted at a private Jerez test in April, where Espargaro also trialled the machinery.
Kallio, who is making the first of his five scheduled wildcard appearances this season, is riding that version of the KTM at the Jerez race weekend.
The Finn, who was 12th and 14th in the two Friday practices, said of the bike: "This is a new version that is based pretty much on the next year's model already.
"For sure it will be interesting to see what the race performance of the new bike is."
Espargaro – who will remain with KTM through to the end of 2020 – found the new bike to be “faster” than the current RC16, especially on used rubber over a race distance, saying he "almost couldn't follow" Kallio.
"I will confirm in the test that the bike was faster, for me it was quite [a lot] faster," said Espargaro. "Especially with used tyres on the race distance, in low grip, and Mika is confirming it.
"I've been [riding] behind Mika in the first of the practices with used tyres this morning, and this afternoon, and almost I couldn't follow him.
"He was turning quite a lot. Mika's fast, but I know how this bike feels in Jerez and it's exactly the same.
"We are going to have a meeting later to know what is going on, but everything looks positive and on the way."
Espargaro confirmed he won't be racing the new bike any time soon.
"For sure it's something interesting for me, but there is something in the rules,” he said when asked if racing the new bike was an option.
"It's not easy to make a new bike like this one, like Mika is using, in one month. You need to make some kilometres and know that it's gonna work – you cannot spend the money for nothing."
KTM reached its "limit" in Jerez
Espargaro was third fastest in FP1 with a 1m39.311s after following Valentino Rossi, but slipped to 11th in the second session and feels KTM has already reached its “limit”.
"I did it [the lap] behind Vale. The last split was nice. It was FP1, we must be happy for sure but it was just FP1 and we knew it.
"The only problem is that we reach more or less the top level of our bike really soon.
"I'm able to do a fast laptime very fast, but then to improve that you need different tools, and I think that we are not on the limit, but we are reaching the limit of the bike.
"So now is gonna be difficult for us, it's going to be easier for them to improve from this morning to qualifying by maybe two seconds.
"So we are gonna be stuck, but anyway, it was really nice.
"We come from the first three races where, in the first two or three corners, we lose, for example, Valentino, and here I was catching him."
Additional reporting by Jose Tabajon