Alonso and Aston Martin announced on Thursday that the 42-year-old Spaniard would remain with the Silverstone team for at least the 2025 and 2026 seasons.
Speaking to the media after the announcement, Alonso revealed he signed a multi-year deal that will keep him associated with the brand beyond his driving days once he decides to retire from F1.
"It's a lifetime project in a way for me, this is the longest contract I ever signed in my career," the two-time world champion said.
"This is something that will keep me linked with Aston for many, many years to come. Let's see which role, let's see how many more years I will drive.
"But even after driving, I will use 25-plus years of experience in Formula 1, plus another 10 or 15 outside F1, so nearly 40 years' motorsport experience in the benefit of a team that gave me this opportunity now in this moment in my career.
"So, this is also very appealing for me and I'm extremely motivated for the next years to come."
On the driving side, Alonso's new contract will take him into the all-new 2026 regulations cycle, when F1 teams will field vastly different cars and power units.
When asked by Motorsport.com how crucial it was for him to sign a longer-term deal that includes 2026, so he could judge how Aston and its new engine partner Honda stack up in the new era, he replied: "Yeah, it was an important point, I will not lie. To commit to a one-year project didn't make sense for me.
"It's not that I had a one-year proposal elsewhere or anything like that - it was just, I was very clear to Aston in the first conversations that the appealing part of this project is just everything that we are building.
"For me it was a must to really enter new regulations with a new project. Part of the decision to stay at Aston is because they are with Honda for 2026, it is because they are with Aramco, the biggest and the best partner in the world.
"We have incredible, talented people in the team now on the technical side that will benefit from the new wind tunnel and the new facilities in Silverstone.
"There were a lot of factors that made 2026 very appealing with Aston."
