Toyota’s buildout of its new Toyota New Global Architecture (TNGA), headlined by the latest Prius and Camry, has progressed to powertrains. Among the first developments out of that gate will be a new 2.0-liter four-cylinder engine called Dynamic Force for both gasoline and hybrid vehicles, a new six-speed manual transmission, two new all-wheel-drive systems, and—most intriguing of all—a new continuously variable automatic transmission.
Toyota offers few specifics on its new 2.0-liter Dynamic Force gasoline inline-four, likely because it will ultimately end up in a plethora of cars and crossovers in various states of tune. The basics, however, are as follows: The Dynamic Force engine will have Toyota’s D4-S port and direct fuel injection as well as an electronically controlled thermostat and an electrically driven water pump; it also is said to be capable of an incredible 40 percent thermal efficiency. That pushes the boundaries of gas-engine thermal efficiency, and the version that will power future Toyota hybrids does even better, at a claimed 41 percent.
Presumably, the 2.0-liter four will be compatible with the new six-speed manual transmission Toyota has developed for “global needs”—fingers crossed that it comes stateside. The transmission is more compact and lighter than Toyota’s current unit and incorporates rev-matching capability.
Continuous Variable Improvements
What about that CVT is so interesting? Toyota’s claim that it will address belt-type CVTs’ worst bugaboo: their laggard, disconnected feel when accelerating from a stop. For those who’ve never experienced it, imagine pressing your foot on the accelerator pedal and hearing the engine rev up out of step with how quickly the car accelerates. This is due to a CVT’s continuous ratio changes, which are realized by shifting a belt along two angled pulleys. Ratio changes chase engine speeds, rather than the other way around; CVTs are designed to keep the engine running at its torque peak to maximize efficiency.
In an effort to give its new CVT the feel of a conventional automatic transmission when accelerating from a stop, Toyota has added a “launch gear.” Essentially, this fixed ratio—not a simulated gear as in some CVTs—is just like a normal transmission’s first gear. As vehicle speed builds, the transmission then shifts out of launch gear and continues as a CVT. Toyota claims this is “unprecedented,” although we found some precedent in transmission supplier Jatco’s CVT7. In that CVT, engine torque enters the CVT as usual but exits on the output shaft to an “auxiliary gearbox” that is, in effect, a two-speed transmission. The difference is that, in the Jatco unit, the car always starts from a stop with the CVT engaged. Toyota claims the new transmission enhances both performance and fuel economy compared with its existing CVT, and with an even wider ratio spread.
Two Ways to AWD
Coming soon to a TNGA-platform Toyota near you is a new all-wheel-drive system. It will have torque-vectoring capability with the ability to distribute torque between the left and right rear wheels, bringing a bit of high-tech verve to future all-wheel-drive Toyotas. Hybrid all-wheel-drive models, which in Toyota’s world typically feature a two-motor hybrid transaxle powering the front axle and an electric motor powering the rear axle, will get a more powerful rear-axle motor in the new E-Four AWD system.
If this seems like an onslaught of powertrain news, well, buckle in. Toyota says it plans to bring “17 versions of nine engines, 10 versions of four transmissions, and 10 versions of six hybrid systems” to market by 2022. The new gas and hybridized 2.0-liter engines, six-speed manual, and new CVT apparently count for just four of those options.