Dynamic Force Engines 2.5-liter four-cylinder
04/28/2017
F or for Toyota, the diesel issue is over in the long run. In Europe, they are cooperating with BMW on diesel engines, while Toyota has stopped all development work on passenger car diesel engines for the remaining markets. Instead, the engineers focused on a new family of gasoline engines that will include 17 variants of nine different engines at the end of the development program. It starts with a four-cylinder with a displacement of 2.5 liters, which Toyota has now presented in detail at the Vienna Motor Symposium.
The 'Dynamic Force Engine' series is part of the new TNGA platform strategy that comes with the new Prius , the C-HR and the Camry presented in Detroit in January already includes three models. The latter also explains why the 2.5-liter engine is the first to come - in both the hybrid and the regular combustion version, it is the most popular engine in Toyota's bestseller Camry.
Compared to the the latest generation of engines, the new TNGA four-cylinder should achieve a thermal efficiency of over 40 percent. In order to achieve the higher specific power with lower fuel consumption and exhaust emissions, the combustion system was fundamentally modified. The basic structure such as the stroke-to-bore ratio and the valve structure have been completely redesigned, with 87.5: 103.4 the 2.5-liter engine is once again significantly longer than its predecessor. The engine's intake valve seat is manufactured using the so-called laser cladding process; together with the new piston design, the wobble ratio and the air flow coefficient are to be increased.
Consumption reduced by 16%
The engine has a new electrical system for variable valve control, a new direct injection system (D-4S) with multi-hole injector and a variably controllable cooling and lubrication system. As already shown with other engines in Vienna at the engine symposium, Toyota also relies on an electric water pump, which not only works more effectively, but is also intended to considerably shorten the pollutant-rich warm-up process of the machine. Thanks to the variable valve control, the engine can also be operated in the Atkinson cycle, depending on requirements.
The consumption of the new four-cylinder is said to be 16 percent lower than its predecessor, and the acceleration time to be ten percent. As before, the new direct injection engine is available in two designs for use as the sole drive sourceand manufactured as a hybrid version in conjunction with an electric drive. The standard engine achieves 205 hp and 250 Newton meters of torque, the hybrid variant reaches 178 hp and 221 Newton meters. Toyota continues to refrain from charging by turbo or compressor. Toyota specifies the specific power at 60 kW /liter, which enables conclusions to be drawn about further displacement variants
