Toyota’s drivetrain boss has revealed the Japanese carmaker will continue to invest in the development of large naturally-aspirated engines, despite an industry-wide focus on downsizing to smaller turbocharged engines.
Speaking with US industry paper Automotive News, Koei Saga said that while Toyota is still working on turbocharging technology for the future, he doesn’t expect to see it sitting across the entire range.
The drivetrain boss said he believes many buyers of models with turbocharged engines are looking for a performance boost, rather than better economy.
Mr Saga said that significant improvements to naturally-aspirated engine technology can be made through advancing the Atkinson cycle - as used with the combustion engines in many hybrid models - rather than the more conventional Otto cycle.
Mr Saga described future development of CVT technology as “crucial and important”, but concedes the transmission is not suited to larger, more powerful models.
Mr Saga believes that while lithium-ion batteries are the future, they cannot currently match the longevity of nickel batteries.
"A lithium ion battery can deliver the same energy in a 30 percent smaller package, but the life span and durability is outstanding for the nickel battery," Mr Saga said.
When questioned about the future plug-in Prius however, Mr Saga said lithium ion batteries were “a must”.
As for EVs, Mr Saga believed the model segment did not show signs of growth, saying that many EV sales were simply "the same wealthy buyers returning to purchase their third or fourth car”.