Mazda revealed the all-new Mazda CX-9 at the Los Angeles Auto Show.A three-row midsized crossover SUV featuring the latest SKYACTIV technology and KODO—Soul of Motion design, the all-new CX-9 is a high-end model of Mazda’s new-generation line-up. The model has been tailored for the North American market, which is expected to account for 80 percent of global sales forecast at 50,000 units annually. Sales launches start from North America in spring 2016.
Now comes the encore: the latest, grandest expression of KODO—Soul of Motion design yet and the high-end model of Mazda’s new-generation lineup. Its cachet is elevated with a proud front fascia that cascades into crisp lines that flow to the rear. Its interior is nothing short of breathtaking, with available Auburn-colored Nappa leather, Japanese rosewood and aluminum. The focus was on authenticity; an experience rather than simply another commodity conveyance.
With the new CX-9, engineers sought to instill driving dynamics befitting of a Mazda—agile handling, tight steering and a responsive, controllable powertrain. To do this, they found smart solutions to keep CX-9’s structure light, yet rigid, with SKYACTIV Technology. They developed a new turbocharged SKYACTIV-G 2.5T engine that delivers instant throttle response, class-leading torque and an estimated around 20-percent increase in fuel-efficiency, based on initial estimates of U.S. EPA testing cycles, making CX-9 among the most efficient vehicles in its class.
Mazda Motor Corporation has enhanced its SKYACTIV-G engine series with the range-topping SKYACTIV-G 2.5T. This 2.5-liter direct-injection turbocharged gasoline engine powers the all-new CX-9 midsize three-row crossover SUV that will go on sale starting from North America in spring 2016.
The SKYACTIV engine series aims to offer customers a combination of outstanding fuel economy and excellent dynamic performance in everyday driving situations. Mazda’s development philosophy is to offer this combination across all vehicle lines, using the most appropriate engine displacement and simplest configuration of technologies for a given vehicle size. Developed in line with this philosophy and based on the naturally aspirated SKYACTIV-G 2.5 featured in the Mazda6 (known as Atenza in Japan), SKYACTIV-G 2.5T is the first turbocharged engine in the SKYACTIV-G series. It delivers exceptional catalog and real-world fuel economy, excellent response without turbo lag, and linear and powerful acceleration in the low- to mid-rpm range where CX-9 drivers spend the vast majority of their time.Maximum torque is 310 ft-lb, comparable with a naturally aspirated 4-liter gasoline engine.
Traditionally, turbocharged engines have suffered from poor dynamic performance at low rpms, including turbo lag, and disappointing real-world fuel economy. SKYACTIV-G 2.5T overcomes these problems with the Dynamic Pressure Turbo, the world’s first turbocharging system that can vary the degree of exhaust pulsation depending on engine speed, and a cooled exhaust gas recirculation (EGR) system that allows the engine to maintain the ideal air-fuel ratio (λ=1) over a wider output range.
Features of SKYACTIV-G 2.5T
- High compression ratio
Mazda engineers achieved a compression ratio 10.5:1, one of the highest for any turbocharged engine with an 89-mm bore size that can run on regular gasoline.
- Dynamic Pressure Turbo
SKYACTIV-G 2.5T is the world’s first turbocharged engine with the ability to change the degree of exhaust pulsation depending on engine speed. At low rpms (below 1620 rpm), the volume of the exhaust ports is reduced by closing a series of valves located just before the turbine that drives the turbocharger. This reduces interference between exhaust pulses and maximizes the energy of each pulse to obtain a high turbine driving force. At higher rpms there is sufficient energy in the exhaust flow and the valves open, allowing the turbine to be driven by a steady flow of exhaust gases as in a traditional turbocharger. Whereas existing variable turbochargers adjust the speed or direction of exhaust gas flowing into the turbine, Dynamic Pressure Turbo is a unique technology that varies the degree of exhaust pulsation.
- Cooled Exhaust Gas Recirculation (EGR)
This system takes some of the inert exhaust gas that results from the combustion process and reduces its temperature by passing it through a cooler before introducing it back into the engine’s air intake. This lowers the temperature of combustion in the engine, preventing knocking, expanding the range in which the engine can maintain the ideal air-fuel ratio and reducing the need to retard ignition timing.
- Inherits SKYACTIV-G principals of efficient combustion
SKYACTIV-G 2.5T is based on the naturally aspirated SKYACTIV-G 2.5 and features the same bore, stroke and bore pitch. Parts of the fuel system, such as the fuel pump and fuel injection system are also shared, helping SKYACTIV-G 2.5T to achieve the highly efficient combustion for which SKYACTIV-G engines are known.
Source: Mazda Press Release.