Although autonomous driving technology was heavily debated, the standout subject at this year’s Tokyo motor show was the decline of diesel and whether electric, hybrid or hydrogen power will be its replacement.

When asked about ‘dieselgate,’ Nissan’s head, Carlos Ghosn, said that though no one could guess with certainty, what is clear is that the scandal “is not going to make diesel more popular in the US,” he said. “In Europe, it will be fair to say that at best diesel will be stable. But we have to be ready for the decline of diesel.”

The Tokyo motor show was full of cars and concepts looking to usurp the fuel, from hydrogen to hybrids. Nissan is firmly focused on electric as the future and on winning over the “heart of the market” rather than competing head on with others. “There is already somebody there doing a very good job, so why go after him?” said Ghosn about a Nissan alternative to the Tesla Model S. “If we want to move somewhere, it will be to crossovers, which are becoming much more popular everywhere.”

Toyota — which, through Lexus is clearly focused on the premium end of the market — unveiled the LF-FC, a  hydrogen fuel cell concept aimed at Mercedes S Class owners. Lexus president, Tokuo Fukuichi, called the car a “high-tech vision of the not so distant future.” But on Toyota’s main stand there were plenty examples of hydrogen and hybrid cars that will be on sale within the next 12 months.

“Hybrids and fuel cell vehicles have both, at one point, been dismissed as oddities,” said Akio Toyoda, Toyota’s President. “Experience has taught us that, while ideas like these come from the fringes at first, they settle down and become the new norm.”

Toyota is focused on hydrogen and used much of this year’s event to publicize the global launch of the Mirai, its first mass-produced fuel cell car.

A sentiment shared by Honda: its President and CEO, Takahiro Hachigo, described his company’s role in the hydrogen economy as providing the key that “Opened up the door to the future.”

“Thirteen years ago, Honda was the ultimate pioneer in realizing the world’s first completely clean vehicle,” said Hachigo, referring to the FCX, its fuel cell car that went on sale back in 2002.

And since then, the company has been constantly improving on the technology. Its latest fuel cell car, the FCV Clarity, which offers a 700km range, will be offered for sale globally.

But hydrogen is very much a fuel for the future, and only a potential version of the future at that. Thankfully, Japanese car companies are also focused on making what little oil’s left go as far as possible.