Jatco’s new CVT8 is key to 2013 Altima’s 38-mpg efficiency

  • 04-Apr-2012 12:31 EDT
Jatco CVT8.JPG

The new CVT8 uses two different internal drive systems, depending on engine application. A belt drive is used on all four-cylinder models (shown). CVTs designed for use with V6 engines feature a chain drive.

Nissan engineers focused on all areas of the 2013 Altima (L42L program) in their quest for greater efficiency. But they credit the car’s new continuously variable transmission (CVT) for contributing a significant portion of Altima’s estimated 38-mpg highway fuel economy.

“I’d say that 40% of the fuel economy is due to the CVT,” said Vishnu Jayamohan, a product-planning executive with Nissan North America.

The new CVT is supplied by Jatco, which is 82% owned by Nissan. Jatco has been in the vanguard of CVT R&D for years, although the company’s product portfolio also includes many planetary-type stepped-gear automatics for front- and rear-drive applications.

Jayamohan, an engineer, told AEI that the CVT features a ratio spread of “around seven—the largest ratio spread in the segment,” he said. The new Altima’s main competitors, including Toyota Camry, Honda Accord, Ford Fusion, and Chevrolet Malibu, use planetary 6-speed automatics with ratio spreads near six.

The CVT8's controls are configured to give the unit the shifting "feel" of a 7-speed stepped automatic, when the transmission is actuated manually using paddles on the steering column. 

380 N·m capacity

The new CVT is branded “Xtronic” by Nissan. According to industry sources familiar with the unit, it is known as the CVT8 (despite its ratio spread) and by its APO internal code. They said its 40% greater operating efficiency and reduced parasitics are due to use of a more efficient pump design and reduced valve body leakage.

Jatco considers the CVT8 (also coded ARO) to be its “global strategic” CVT, designed to handle input torques up to 380 N•m (280 lb•ft). With this breadth of capability, the CVT8 will replace Jatco’s CVT2 and CVT3. It will be used with both the 2.5-L I4 and 3.5-L V6 Altima engines for North America. (The two transmission applications differ in the size of their torque converters and number of clutch plates, engineers said.)

CVT8 joins another new model, the CVT7, in the company’s portfolio. Known internally as APO, the CVT7 replaces the CVT-1 and is aimed at input torques below 180 N•m (133 lb•ft). CVT7 will be used in the next Nissan Versa, among other compact vehicles. Its technology trump card is a planetary gearset engineered into the CVT for improved efficiency. It also features a slimmer drive belt and new pulleys with a smaller internal diameter, which provides a tighter “wrap” at launch, according to engineers.

The new Jatco CVTs share approximately 85% of their bills of material. With the new Altima in final calibrations, Jatco has a team of engineers stationed at Nissan’s Arizona proving ground to support the car’s launch.

Author:
Sector:
Mentions:
Share
HTML for Linking to Page
Page URL
Grade
Rate It
4.24 Avg. Rating

Read More Articles On

2016-11-15
Freudenberg Sealing Technologies has expanded its LESS (Low Emission Sealing Solution) lineup to include new products designed to address challenges associated with powertrain friction, smaller spaces, lighter weight vehicles and growth in the electric mobility vehicle arena.
2016-11-15
At least for this moment, all is right with the world as Mercedes-Benz reinstates a new-age version of its iconic inline six-cylinder engine.
2016-11-15
Tanktwo, a Finland-based startup company is rethinking the basic battery cell and challenging the fundamental economics and operational assumptions of EVs. The ingenious concept is worth engineers' attention.
2016-11-14
Conti’s 48-V system will be standard equipment on both gasoline and diesel versions of the Scenic Hybrid Assist model. It is the first of multiple 48-V production announcements coming over the next few years.

Related Items

Training / Education
2010-03-15
Training / Education
2010-03-15
Article
2016-10-20