Robert Downey Jr. on 'Downey's Dream Cars' & 'Tropic Thunder' Sequel (Exclusive)

Robert Downey Jr. is going from saving the world as Iron Man on the big screen to saving the environment in his new Max series "Downey’s Dream Cars.”

“Extra’s” Melvin Robert was with Robert and his wife Susan at the premiere Friday.

The show focuses on a team of experts as they restore six classic cars from Robert's own collection to make them more eco-friendly.

Robert told Mel why the project was so important to him, saying, “I love design and I started collecting these cars and a lot of it was like I thought I was this successful movie guy and I am supposed to start collecting things... and turns out I am not really a gear head. I would rather drive the safest, newest, cheapest car than the coolest, oldest car."

He went on, "I am also thinking about my family's overall health and safety, so I thought, 'How can I make a statement with these that’s also keeping with this new directive with the FootPrint Coalition?'”

Robert heads up the FootPrint Coalition, which gathers investors interested in scaling technology to restore the health of the planet.

Mel asked Susan to rank her husband's obsession with cars from one to 10. “I think he has a very healthy, little-boy interest in cars," she said. "I think dudes like cars for the most part.”

“I think you are at a nine, to be honest," she told Robert. "You do watch car shows on TV.”

Robert copped to a love of shows like that, saying, "I can drive almost any kind of vehicle or some trucks, drive stick pretty well… Three are generations now that only really understand cars that drive themselves; there is something to be said for really feeling the road experience."

He went on, “Also, classic cars are a pain in the ass... It's like 'The Exorcist' and coolant is flying out of the glove box… I felt like these cars became a lot safer a lot greener, and it was certainly fun to shoot.”

The couple's kids are getting in on the show, appearing on episodes. Mel warned Robert his son Exton, 11, could be coming for his job!

Robert, who is the father of son Indio Falconer, 30, from his first marriage, has two kids with Susan — Exton and 8-year-old daughter Avri Roel. How will he spend Father's Day?

Susan said, “We are actually celebrating by being pretty chill at the house with lots of gifts, good food, and a lot of love.”

Mel had to ask about a "Tropic Thunder" sequel after Tom Cruise said he wanted to do one, to which Robert said cagily, “That’s kind of a yes, and then we will figure out what the title is.”

"Downey's Dream Cars" streams June 22 on Max.