Romain Grosjean hopes for eventual return to Renault F1 team

Amid the uncertainty over the team's future last September, Grosjean decided to leave Lotus after a four-year racing stint and join F1 newcomer Haas for 2016.

Following six months of protracted negotiations, French manufacturer Renault confirmed in December it will return to F1 in 2016 as a full works outfit through a takeover of Lotus.

Grosjean, who was a test driver for Renault in 2008 and made his F1 race debut with the outfit in mid-2009, said it was tough to leave Enstone but has not closed the door to a return.

"Enstone is a big chapter of my life," Grosjean told Autosport.

"The people there are friends and family and I know every corner of the factory.

"Some years, I was even there for Christmas. When I lived in the UK, I went there on December 24 with my brother-in-law.

"It was hard to leave but we won't be too far down the paddock.

"And who knows? Maybe in three or four years' time, they produce a world championship winning car and they call me and say let's win together.

"That would be ideal. As a Frenchman that would be huge."

Grosjean endured a difficult final season with Lotus as the team's progress was hampered by budget restrictions that meant it ended the campaign with a car much the same as it was at the start of the year.

With those limitations removed, Grosjean believes the team has the facilities and the people to move back up the field.

"It's a world championship-winning team," he said. "The wins in 2005 and 2006 are not that long ago.

"There is a lot of potential in Enstone.

"I've known this for a long time and Enstone knows but it's hard to prove it if you don't have the tools that you need."

GROSJEAN'S LONG ENSTONE HISTORY

2006/07: First affiliated with the then-Renault team as a member of the manufacturer's Driver Development scheme while racing in Formula 3

2008: Becomes Renault's F1 test driver and makes debut in mid-season Barcelona session (pictured below)

2009: Called up from GP2 programme to F1 race seat to replace Nelson Piquet Jr from Belgian GP amid fallout from Crashgate scandal revelations, but struggles with crisis-hit team and is dropped at end of year

2011: After rehabilitating his career with Auto GP and GP2 titles, returns to Enstone fold as a test driver and drives in Friday practice at year's final two grands prix

2012: Returns to F1 grid as race driver for now Lotus-branded team alongside Kimi Raikkonen. Scores three podium finishes but year marred by crashes, including Belgian GP pile-up that earns him a race ban

2013: Grosjean secures career-best seventh in world championship with Lotus, taking six podium finishes along the way

2014/15: Lotus team increasingly hampered by financial problems, but Grosjean raises its spirits with 2015 Belgian GP podium before resolving to leave for Haas as saga of Renault takeover drags on