Mitsuhisa Kato, the executive vice president in charge of global r&d at Toyota Motor Corp., expects the carmaker’s so-called Toyota New Global Architecture, or TNGA, to result to big weight savings and fuel economy gains. Kato said that via TNGA -- due to arrive in 2015 –Toyota will be able to slash overall vehicle weight by up to 20 percent. He also said that a new TNGA engine should achieve thermal efficiency rates greater than 40 percent, compared with the 38.5 percent thermal efficiency of the most efficient engines in Toyota's lineup – those fitted in the Prius and Crown hybrids. This means that the TNGA energy allows for more energy from internal combustion to be captured to power the wheels, while less energy is lost through heat.
According to Kato, a shift to rates above 40 percent could translate into fuel efficiency gains of under 10 percent via engine performance alone. Satoshi Ogiso, managing officer in charge of global product planning, drivetrain and chassis engineering at Toyota, expects the new TNGA hybrid engine to have efficiency rates of around 42 percent.
Gasoline engines not mated to an electrical hybrid system, currently have thermal efficiency rates of around 36-37 percent, which should improve to around 40 percent with the advent of TNGA. The improvement will be achieved through better combustion and lesser friction. Kato remarked that TNGA overhaul will be applied first to the small-car platform used for the Prius.