Toyota Motor Corp. is eyeing to trim the weight of its vehicles by up to 20 percent and to increase their fuel economy by 2015, according to Mitsuhisa Kato, executive vice president in charge of global r&d. Kato remarked that the weight savings will come on the heels of the so-called Toyota New Global Architecture, or TNGA.
He also disclosed that a new TNGA engine is expected to achieve thermal efficiency rates greater than 40 percent, compared to the 38.5 percent thermal efficiency of Toyota’s most efficient powerplants, those fitted in the Prius and Crown hybrids.
An engine with higher thermal efficiency captures more energy from internal combustion to run the vehicle and less is lost through heat. Kato estimates that thermal efficiency rates of over 40 percent could translate into fuel efficiency gains just under 10 percent through engine performance alone.
Satoshi Ogiso, managing officer responsible for global product planning, drivetrain and chassis engineering, disclosed that the upcoming TNGA hybrid engine will have thermal efficiency rates of around 42 percent.
He added that for gasoline engines not paired to an electrical hybrid system, the thermal efficiency rates will be around 36 or 37 percent. With the TNGA, the rates will improve to around 40 percent. The improvements will be achieved through better combustion and reduced friction. The TNGA will be first applied to the small-car platform underpinning the Prius, Kato said.