"There are very few hard-core, dark-green environmentalists, but those who are strictly hybrid buyers," he said.
"Dark greenies are very savvy about the product. Sometimes they even educate our salespeople.
"They know that 90 per cent of our battery is recyclable and dispensed of properly.
"Dark greens won't even look at diesel."
However, he wouldn't rule out Lexus making a diesel hybrid in the future.
"The good thing about our hybrid system is that it can be adapted to diesel," he said.
Another attraction of hybrids was that the production process was becoming cheaper, making the vehicles more affordable.
"The RX hybrid is the cheapest Lexus hybrid yet and represents excellent value for money," he said.
"Diesel vehicle prices are going up, but hybrid prices are coming down."
Roca said they needed an entry level hybrid to attract younger buyers but said the planned mid-sized HS250h hybrid sedan was not yet confirmed for Australia.
"I don't know if it would be entry level either. It's more of an ES size.
"But we do need an entry-level hybrid.
"Our average hybrid owner is five years older than the equivalent petrol model buyer.
"With the petrol RX the average age is 45, so the hybrid is about 50, but I think the average age will come down for the RX400h mainly because of the more affordable price."
Roca said he hoped other manufacturers would turn to hybrid technology.
"I can't wait for others to go hybrid because then we won't have to educate the market on our own," he said.