Adrian Newey said the new Aston Martin had showed “promising results” in its first on-track session at the Hungarian Grand Prix.
Fernando Alonso set 13th fastest time in the session, 2.475 seconds from the pace set by Ferrari’s Charles Leclerc, but team-mate Lance Stroll had a rear suspension failure.
Alonso’s time is a significant step forward from the four-second margin that has generally separated Aston Martin from the pace so far this season.
Team boss Newey said: “Very early days in terms of understanding the new package. Provisional results are promising.
“We will have some more steps in Monza and Baku, so it is the first part of our planned upgrade. Very short on parts so being careful with it and trying to learn all about it.”
Aston Martin’s engine partner Honda will also take an upgraded power-unit to the next race, the Dutch Grand Prix, after Formula 1’s four-week summer break.
The car is virtually new, only the front suspension, engine and gearbox are the same as at the last race in Belgium a week ago.
Even the chassis has been changed, with a significant amount of weight being taken out of it, needing a full re-homologation process from governing body the FIA.
Stroll’s left rear suspension appeared to break as he rounded Turn Three with about 20 minutes left of the session.
Newey said in a news conference after the session: “Everybody is feverishly trying to understand what went wrong and it is only once we have an understanding that we can comment on what we do next.
“The area involved is not what has been changed, so in that sense it was very unexpected.”
Alonso was sent out straight away as soon as the session restarted.