Jenson Button believes that the step forward made by Honda with its power unit ahead of the 2016 Formula 1 season is the biggest in 14 months.
Button and his McLaren team endured a miserable 2015 season largely thanks to issues with the power unit provided by Honda upon its return to the sport as an engine supplier.
The Japanese manufacturer came under heavy fire throughout the season, leaving it with plenty of work to do over the winter to avoid a repeat in 2016.
McLaren debuted the new power unit for this season on Tuesday in Barcelona, with Button getting his first taste of it when he took over from teammate Fernando Alonso on Wednesday.
Speaking after his day in the car, Button said that the progress made by Honda was not only noticeable, but also impressive.
“I would say it’s the biggest improvement yet with the power unit over the last 14 months, which is good,” Button said.
“I think the improvement is good, but obviously we’re still a long way off the other guys, and you can see that in the speed traps. You can definitely feel the difference though, in the initial part of the straight.
“We’ve got the reliability sorted I think, so we can really, really push the performance with the power unit.”
Although Button is confident that McLaren can be more competitive in 2016 as a result of the progress made by Honda, he still feels there is plenty of work to be done over the remainder of the winter testing period.
“I’m hoping we won’t be hanging off the back [of other cars], but there’s still a lot of work before I feel that we’re properly competitive yet,” Button said.
“There’s still a lot of work needed over the next two days to find a set-up that really works for us, because we’re not there.”