JSAE Exposition 2015: Japanese OEMs unveil new models and innovations
Mazda debuts MX-5, Nissan shows front-wheel drive HV, Suzuki displays updated R06A engine
This report contains a summary of the all-new vehicles, powertrains and newly developed body structure exhibited by Japanese OEMs at JSAE Exposition 2015 held on May 20-22.
|Nissan||Hybrid system for FWD vehicles,Micro electric vehicle "Nissan New Mobility Concept"|
|Suzuki||Renewed R06A engine and Auto Gear Shift (AGS)|
|Mazda||All-new fourth-generation MX-5 (known as the Roadster in Japan)|
|Isuzu||Facelifted Elf Hybrid with new EV drive mode|
|Daihatsu||"D monocoque" lightweight high-rigidity body structure|
Related reports: JSAE exposition 2015 (Jun. 2015)
Envisioning future of powertrains for passenger cars (1)
Toyota and Honda showcase direct-injection turbo engines
Toyota Mirai FCV cutaway model on display
Mazda2 features latest body structural technologies
Latest OEM safety and autonomous driving technology
Nissan: Powertrain for X-Trail Hybrid
|Nissan's hybrid system for FWD vehicles (motor and CVT on the right)|
Nissan exhibited a cutaway model of a hybrid powertrain for front-wheel drive (FWD) vehicles. The powertrain is used in the X-Trail Hybrid that Nissan released in April 2015 in Japan. It features Nissan's 1-motor 2-clutch hybrid system dubbed Intelligent Dual Clutch Control System that Nissan has been using on rear-wheel drive models such as the Infiniti Q70 (known as the Fuga in Japan) and the Infiniti Q50 (sold as the Skyline in Japan). The system consists of the MR20DD direct-injection engine that has been optimized for hybrid use, XTRONIC CVT and lithium-ion batteries to achieve nimble, linear acceleration. It also gives better fuel economy than average vehicles of this class, at 20.6km/liter (2WD model) and 20.0km/liter (AWD) in a JC08 test method. The combination of a 2.0-liter engine and a motor generates more torques than a 2.5-liter engine in all speed ranges from low to high rpm.
Main specifications of the hybrid system for FWD vehicles (cutaway model exhibited)
|Max. power||108 kW (147 PS)/6000rpm|
|Max. torque||207 N･m (21.1 kgf･m)/4400rpm|
|Electric motor model||RM31|
|(Notes) 1.||The 4-cylinder direct-injection MR20DD engine is optimized for hybrid use.|
|2.||Front-wheel drive hybrid versions are available with the 2014 models of the Nissan Pathfinder and Infiniti QX60 in the United States but not with the 2015 model as of mid-June 2015.|
Nissan New Mobility Concept, micro electric vehicle
|Nissan New Mobility Concept (tandem model)|
Nissan exhibited a micro EV called Nissan New Mobility Concept. Nissan has been conducting various demonstration tests of the EV in several places. In October 2014, Nissan launched a large-scale public car-sharing demonstration program for registered members in the city of Yokohama using 50 Nissan New Mobility Concept cars. The service is to continue until September 2015. More than 10,000 people have registered for the service. The member can simply hop into the nearest New Mobility Concept vehicle, drive to the desired destination, and leave it for the next person at a convenient station (located at dozens of places in the city).
Nissan New Mobility Concept and public car-sharing demonstration program in Yokohama
|Nissan New Mobility Concept||Seating||2 persons|
|Length × Width × Height||2340mm × 1230mm × 1450mm|
|Max. speed||Approx. 80km/h|
|Cruising range||Approx. 100km|
|Public car-sharing demonstration program in Yokohama, Japan||* Members must receive instructions before signing up as members. * The service is limited to roads other than expressways and limited highways.|
Suzuki: Renewed R06A engine and Auto Gear Shift
Suzuki exhibited the renewed R06A engine and Auto Gear Shift (AGS) fitted in the all-new Alto that was launched in December 2014. Featuring a newly-developed, 60kg lighter platform and a renewed engine, the all-new Alto has achieved class-top fuel economy of 37.0km/liter (2WD, CVT model).
Suzuki also exhibited the Alto Turbo RS that was launched in March 2015 and fitted with the AGS. The AGS is an automated manual transmission (AMT) with automated clutch and gear-shifting. Suzuki engineers studied how experienced drivers operated manual transmission and reproduced their techniques in developing automated operation programs.
|Renewed R06A engine with AGS on the right side||Alto Turbo RS with AGS released in March 2015|
Comparison of engine specifications of Alto series models
|Renewed R06A (Note 1)||Turbocharged R06A (Note 2)|
|Fitted in the all-new Alto launched in December 2014||Fitted in the Alto Turbo RS launched in March 2015|
|Water-cooled 4-cycle 3-cylinder engines|
|Valve train||DHOC intake/exhaust VVT||DHOC intake VVT|
|Bore × stroke (mm)||64.0 × 68.2|
|EGR system||External EGR||n/a|
|Max. power (kW/rpm)||38/6,500||47/6,000|
|Max. torque (N･m/rpm)||63/4,000||98/3,000|
|Fuel consumption (JC08)||37.0km/L (2WD/ CVT)||25.6km/L (2WD/ 5AGS)|
|(Notes) 1-1.||The renewed R06A engine generates a strong tumble flow in the cylinder to increase the speed of combustion. It also uses an external EGR system to lower the combustion temperature to prevent knocking and reduce the pumping loss in the intake stroke.|
|1-2.||The all-new Alto (2WD, CVT model) launched in December 2014 is built on a platform that was reduced in weight by 60kg. It has achieved JC08 mode fuel economy of 37.0km/liter, one of the highest among gasoline-fueled vehicles other than hybrid vehicles.|
|2-1.||The renewed R06A turbo engine with intake VVT is fitted in the Alto Turbo RS. It features high-tumble intake port and high-efficiency turbocharger. As a result, the turbo lag has been reduced by approximately 20% (compared to the conventional R06A intake VVT turbo engine) which improved the turbocharging response.|
|2-2.||The AGS was tuned for pleasant shift feel by speeding the shift timing.|
Auto Gear Shift (AGS): Tuned to deliver "pleasant shift feel"
|Goal||The AGS is an automated manual transmission in which clutch and gear-shifting operation is done automatically. Suzuki studied the way experienced drivers operated the manual transmission and developed a program that duplicates their techniques and delivers "pleasant shift feel" to the driver.|
|Mimicking best driver's technique||<Clutch disengagement> A good driver disengages the clutch by controlling the accelerator pedal without causing sudden stall or engine revving. This reduces deceleration feel.|
|<Gear-shifting> A good driver shifts gear accurately as well as swiftly to shorten the stall time (idle run time).|
|<Clutch engagement> A good driver swiftly puts the clutch in a partially engaged condition to avoid a shock, and depresses the accelerator pedal while feeling the clutch engagement for smooth acceleration.|
|Model-based tuning||At present, the AGS is fitted in two mini passenger cars (Alto, Alto Turbo RS) and three mini commercial vehicles (the Alto van, Carry, and Every). Suzuki engineers studied how each model was driven and used and tuned all applicable models accordingly. For instance, the Alto Turbo RS follows a faster clutch operation for more direct driving feel to achieve sporty drivability.|
|Creeping||The AGS also enables creeping through fine control of the partial clutch engagement.|
Mazda: All-new Mazda MX-5
Mazda exhibited the all-new Mazda MX-5 (known as the Roadster in Japan) that was unveiled on May 20, the first day of the JSAE 2015 Exposition, and released for sale the following day. Fully remodeled for the first time in ten years, the fourth-generation Roadster features Mazda's latest SKYACTIV technology and "Kodo - Soul of Motion" design theme. The car is given a design that will "stay timeless for a quarter of a century."
With the newly developed direct-injection 1.5-liter SKYACTIV G1.5 gasoline engine positioned behind the front axle (a 2.0-liter engine is used in the previous model), the all-new Roadster has the 50:50 front-rear weight distribution. The newly developed 6-speed manual transmission for front-engine rear-wheel drive system dubbed the SKYACTIV-MT and a 6-speed automatic transmission are available. The 6-speed SKYACTIV-MT features a light, moderate and crisp shift feel as if the shifter is drawn into gear from mid-shift position. The 6-speed automatic transmission features a blipping function for sporty and powerful driving performance. This function automatically increase engine speed the instant the driver shifts down, adjusting engine rpm to match the selected gear. The result is quicker shifts as well as better continuity and response in deceleration when shifting down.
Mazda developed a new platform dedicated to the MX-5 in which the use of aluminum and ultra-high tensile steel in the body was increased to 71% (from 58% in the previous model). It also adopts a body structure that is lighter and more rigid as well. As a result, the all-new Roadster has achieved weight reduction of more than 100kg resulting in a vehicle weight ranging between 990 and 1,060kg.
|Mazda's all-new fourth-generation MX-5 (sold as the Roadster in Japan)||Chassis of the fourth-generation MX-5|
Main specifications of the Mazda MX-5 (basic model)
|New model||Previous model|
|Curb weight (kg)||990||1,120|
|Max. power (kW/rpm)||96/7,000||125/7,000|
|Max. torque (N･m/rpm)||150/4,800||189/5,000|
|Transmission||SKYACTIV-MT (6-speed)||MT (6-speed)|
|Fuel consumption (JC08) (km/L)||17.2||11.8|
(Note) 6-speed AT is available on both the new and previous models.
Mitsubishi: Outlander PHEV
Mitsubishi exhibited a cutaway model and drive battery of the Outlander Plug-in Hybrid EV (PHEV). The Outlander PHEV is fitted with a 12kWh lithium-ion battery, a front motor, a rear motor and a generator. The all-electric range in JC08 mode was increased from 60.2km to 60.8km when the model was facelifted in June 2015 .
|Cutaway model of the Outlander PHEV||Lithium-ion battery on the Outlander PHEV|
Main specifications of the Outlander PHEV
|(Notes) 1.||MIVEC stands for Mitsubishi Innovative Valve timing Electronic Control system, a generic name of Mitsubishi's variable valve timing systems. The 4B11 engine has total displacement of 2.0 liters.|
|2.||Overall length and vehicle weight are those measured after renewal in June 2015.|
Isuzu: Facelifted Elf Hybrid truck with EV drive mode
Isuzu exhibited the facelifted Elf Hybrid that was released for sale in April 2015. It features an EV drive mode and the “Smart Glide+e” system that enables the truck to run by the vehicle’s inertia with an expanded motor driving range.
|Isuzu Elf Hybrid with a new hybrid system||Powertrain of the Isuzu Elf Hybrid. The drive motor is not positioned on the driveshaft. Its driving force is transmitted via power take-off (PTO) to the driveshaft.|
Remodeled Elf Hybrid
|New EV drive mode||An EV drive mode was added in which the vehicle runs on a motor alone when driving at night or in a residential area where silence is top priority. It has EV cruising range of 2 to 3km after full charge. The EV mode is automatically canceled when the accelerator pedal is depressed or the vehicle speed rises to 25 to 30km/h.|
|When in EV mode, the engine is disengaged from the drivetrain by clutch but keeps idling to maintain enough driving force for engine accessories.|
|Improved Smart Glide+e system||When the vehicle is running at a constant speed with the accelerator pedal pressed lightly, the Smart Glide+e system automatically disengages the clutch and allows the vehicle to coast by inertia to save fuel. The motor supports when the driving force falls. The system optimally controls "inertia driving (coasting) and energy regeneration" and "motor-supported driving" according to the quantity of acceleration pedal operation to improve fuel economy. The engine remains idling as in EV driving mode.|
|The motor output was increased as part of the latest remodeling. The motor driving range of the Smart Glide+e system was expanded and the engine idling rpm during Smart Glide mode was reduced to improve fuel economy.|
Daihatsu: All-new Move built on "D monocoque" lightweight highly rigid body
Daihatsu has developed a lightweight highly rigid body structure dubbed "D monocoque" that was adopted in the all-new Move that went on sale in December 2014. The company ended use of the conventional reinforcements and developed a new rigid body structure with all side outer panels near windows formed with thick, high tensile steel panels. Daihatsu achieved weight reduction of approximately 20kg from the previous model through new body structure as well throughthe use of plastic outer panels.
Although Daihatsu succeeded in reducing the body weight by 20kg as mentioned above, it added partial underbody reinforcements to increase the structural rigidity. This has led to significant improvement in steering stability and ride. These additional reinforcements weigh about 14 kg. Consequently, the total body weight reduction is around 6 kg. The newly developed lightweight high-rigidity body structure contributes to reducing fuel consumption and cutting costs. With this in mind, Daihatsu is working on development toward rolling out the "D monocoque" technology to other vehicles and strengthening Daihatsu's entire range.
Newly-developed "D monocoque" lightweight, high-rigidity structure
Weight reduction with "D monocoque" body and resin-made outer panels
|D monocoque||Previously, the Move was built in a three-layered structure consisting of inner panel, reinforcement and outer panel. The inner panel and reinforcement layers provided the vehicle's body strength. The outer panel only played a design role and was not as strong as other layers. The use of reinforcements generated structural breakpoints at an edge of reinforcement.|
|The new lightweight, high-rigidity body structure "D monocoque" features side outer panels (near doors) that are made of thick, high tensile steel that are integrated with each other. The new structure is a two-layer structure without reinforcements and the load is borne by the entire body structure. The removal of reinforcements has also eliminated structural breakpoints.|
|Plastic outer panel||Coupled with the effect of replacing steel-made outer panels with plastic panels, Daihatsu succeeded in reducing the body weight by approximately 20kg. For instance, the fuel lid, rail cover and integrated fender-spoiler back on the new Move are made of plastics.|
Reduced weight is used to improve driving, ride and other performances
|Although Daihatsu succeeded in reducing the body weight by 20kg as mentioned above, it added partial underbody reinforcements to increase the structural rigidity. This resulted in a significant improvement in terms of driving performance and ride. These additional reinforcements weigh about 14 kg. Consequently, the total body weight reduction is around 6 kg.|
|The increased structural rigidity has led to better driving stability and the absence of structural breakpoints associated with reinforcement has led to reduced noise and vibrations. The increased underbody rigidity has led to better controllability and rear tires' road hugging feel. The reduced weight and reduced use of material and part count have cut cost which contributes to keep affordability of the vehicle price.|
<Automotive Industry Portal MarkLines>