Pascal Wehrlein thinks it would be realistic to expect a five second drop in lap times next year.
The German is among a select few drivers who have already tested Pirelli's 2017 tyres.
Speaking of his experience with the tyres, Wehrlein said: "I can't say much, but yes - the tyres are faster."
"Five seconds per lap (faster) is quite realistic," he added. "Whether it is six seconds or four, we will have to see, but it will be much faster. On top of that, the wide tyres look much better."
Some people, including Pirelli motorsport boss Paul Hembery and Ferrari driver Sebastian Vettel, have said that how big the 2017 lap time improvement will be is hard to describe because the 2015-based test cars are not yet producing enough downforce.
Wehrlein said: "We will have to see how it will be with the 2017 cars, but the new tyres offer more grip. That is a fact."
Bahrain International Circuit - Winter testing