Host Jay Leno smiles during a panel for his upcoming television series "The Jay Leno Show" at the Television Critics Association Cable summer press tour in Pasadena, California August 5, 2009.[Agencies]

LOS ANGELES - After 17 years of late night TV chat, Jay Leno says he's working harder than ever to fill his eagerly-anticipated new prime-time show with comedy.

"It's a lot of material to fill. It is a lot of jokes. This is lot more work. A lot more work. You're doing probably three shows worth of comedy every night," Leno told reporters on Wednesday.

"On 'The Tonight Show' we had maybe two talking guests and a band. That's not a lot of work for me. But this will be a lot more work," he said.

Leno, 59, said "The Jay Leno Show" was heavier on comedy than talk and that he planned to open each night with an 8-12 minute comic monologue, which takes about 5-6 hours to prepare every day.

And with just one celebrity guest each night, he has hired a team of upcoming young comedians as "correspondents" to give an oddball take on the news of the day and topical issues.

One segment, already taped ahead of the September 14 debut of his 10 pm, five nights-a-week experiment for NBC, involves a visit to a retirement center to teach seniors about the whys and wherefores of the Twitter social phenomenon.

"It is very gentle, very kind. But it is just funny," said Leno, admitting he was "not a real Twitter person" himself.

The most exciting new venture for Leno, an avid collector of vintage cars, is the installment of a race car track outside his TV studio in suburban Los Angeles.

Celebrities will be invited to power round the track against the clock in an electric car challenge for a place on a roll of honor of the fastest times over the season.

Leno said actor Tom Cruise and "Grey's Anatomy" star Patrick Dempsey were among those eager to take part.

Leno's move from 11.30 pm to the prime-time 10 pm slot traditionally occupied by expensive scripted drama on leading U.S. networks is being closely watched by the industry as NBC struggles to retain audiences and cut costs in the face of declining advertising revenue and increased competition from videogames and social networking.

"We can do five shows for less than the price of one 'CSI' or 'Law & Order' episode," he said.

But Leno again shrugged off suggestions that the future of NBC, currently lagging in last place in terms of viewership among the four major TV networks, hinged on the success or failure of his new venture.

"We're not here to revolutionize anything or change the world. It is just a comedy show," he said. "We'll try this and see what happens. I just work here."