|The new 3-Cylinder HR12DE engine. Click to enlarge.|
In Yokohama, Nissan Motor Co., Ltd. outlined the range of fuel-saving technologies—including 3- and 4-cylinder engines, CVT transmission with stop-start system and new hybrid system (earlier post) to be introduced on new models to be launched in fiscal year 2010. The technologies are the result of the company’s research and development efforts based on Nissan’s mid-term environmental action plan Green Program 2010 (NGP 2010).
While zero emissions is the ultimate goal, the company is committed to ongoing innovation in technologies that increase efficiency and reduce emissions. As a result, Nissan is offering a suite of automotive technologies, including CVT, Idling Stop (Stop-Start), hybrids, and clean diesel, capable of achieving the best-in-class (1.0-1.5L class not including hybrid vehicles) fuel economy and CO2 emissions.
In Japan, the New March will be launched this month equipped with idling stop technology achieving a 26 km/L fuel economy (61 mpg US, 3.85 L/100km), followed by the Clean Diesel X-TRAIL with automatic transmission and the Fuga Hybrid luxury sedan.
Newly Developed Nissan March Compact Car Powertrain. The New March will feature Nissan’s newly developed compact car powertrain, which is anchored by a new 3-cylinder engine and next-generation XTRONIC CVT (Continuously Variable Transmission).
Developed in pursuit of lighter weight and a smaller size than previous engines in the compact car class, the new 3-cylinder 1.2-liter HR12DE engine requires fewer moving parts compared to the more commonly used 4-cylinder engines. By applying bore circularity machining to the cylinder block, friction has been reduced by 20% (compared with conventional 4-cylinder engines). Moreover, improved NV (noise vibration) performance—at a level equivalent to that of a 4-cylinder engine—has been achieved by adjusting the weight balance of the engine’s rotary shaft.
The new XTRONIC CVT utilizes a one-piece structure equipped with a sub-planetary gear. Its compact, lightweight design is 10% smaller and 13% lighter than previous CVT designs, while also achieving a 30% friction reduction for powerful acceleration performance, quiet operation and improved fuel economy. Its gear ratio of 7.3 (versus a conventional CVT’s 6.0) is the world’s largest among automatic transmissions equipped passenger cars, according to Nissan.
A new Idling Stop system has also been adopted and includes an internal lock function using the sub-planetary gear. The engine can be restarted on a sloping road (angle of 6% or less) without sliding backwards. And, by accurately measuring the crankshaft position during engine shutdown, the engine restart time is shortened.
Clean Diesel X-TRAIL with Automatic Transmission. The automatic transmission X-TRAIL equipped with a clean diesel engine (M9R) will be launched this month in Japan. The vehicle will be compliant with the country’s post-new long-term regulations.
Along with the use of highly precise consolidated engine control, the AT Clean Diesel X-TRAIL utilizes a new highly dispersive lean NOx trap (LNT) catalyst, which is being put to practical use for the first time. The highly dispersive LNT catalyst uses noble metal particles, such as platinum, microparticulated to approximately 40% and arranged effectively. This innovation address the problem of efficiency degradation caused by decreased surface area associated with noble metal aggregation experienced in conventional catalysts.
As a result, a reduction in noble metals and stable exhaust emission control have become possible, enabling the use of a clean diesel engine compatible with the post-new long-term regulations in automatic transmission-equipped cars. The catalytic device will be manufactured at Nissan’s Yokohama Plant.
High-Efficiency Hybrid System. Nissan has developed a 1-motor, 2-clutch parallel full hybrid system. It utilizes an electronically controlled clutch positioned between the engine, motor and drive wheels.
The hybrid system allows for the elimination of friction by completely disconnecting the engine from the system during electric driving or deceleration. The battery is charged efficiently by the engine while driving, while the rotational energy of the wheels is used for energy regeneration. When the clutch is engaged, the engine, motor and wheels are directly connected, so the system also achieves responsive acceleration for sporty driving. In addition, accurate control allows the engine to be stopped more frequently. During test demonstrations conducted in city conditions, it was found that the engine was in a halt condition for almost 50% of the driving time.
The motor is powered by a laminated lithium-ion battery featuring the same structure as the one used on LEAF, Nissan’s electric vehicle. The lithium-ion batteries are used to deliver high-response linear acceleration and fuel consumption equivalent to that of compact cars. The batteries are supplied by Automotive Energy Supply Corporation (AESC), a subsidiary jointly established by Nissan and NEC Corp. of Japan.
The hybrid system is scheduled to launch on the Infiniti M in late 2010.
1.5-liter Engine with Dual Injectors. Nissan’s new 1.5-liter engine (HR15DE), the world’s first mass-produced 1.5-liter engine with dual injectors (2 compact injectors per each cylinder), will also launch in FY2010. (Earlier post.)
The dual injectors stabilize combustion by reducing the size of the particles sprayed in the form of a mist by approximately 60%. Improved thermal efficiency and reduced inhalation resistance have been achieved by combining the injectors with Continuously Variable valve Timing Control (CVTC), which continuously changes the opening-closing timing of the inlet and exhaust valves. As a result, fuel economy has been improved by approximately 4% compared to Nissan's conventional engines in the same class.
In addition, more efficient burning helps to control the hydrocarbons in the exhaust gas and reduces the amount of noble metals needed for exhaust purification. The engine is mounted on the Nissan JUKE, which was launched in Japan in June 2010.
1.6-liter Direct Injection Gasoline Turbocharged Engine. Nissan has developed a new 1.6-liter 4-cylinder MR16DDT engine with Direct Injection Gasoline technology —combining a turbocharger with a low displacement engine to achieve both higher power output and lower fuel consumption. It also adopts inlet and exhaustion CVTC and hydrogen-free DLC(Diamond Like Carbon) coating, as well as other new technologies such as the new friction-reduced valve spring.
The MR16DDT engine achieves power equivalent to that of a 2.5-liter engine, along with the fuel efficiency equivalent to a 1.8-liter engine. The new engine will be available in the Nissan JUKE in the second half of FY2010.