From ALTIMA TECH
The XTRONIC CVT-M6 continuously variable transmission is the world's first steel-belt CVT capable of being used on front-wheel-drive cars powered by a large 3.5-liter engine. Featured on the Nissan Teana with the VQ35DE engine, the XTRONIC CVT-M6 enables the VQ engine to display its overwhelming power to the maximum extent and also delivers smooth driving performance.
The XTRONIC CVT-M6 pro-vides seamless shifting and smooth acceleration as the world's first steel-belt CVT for use on front-drive cars with a large-displacement engine.
How it Works
While automatic or manual transmissions use multiple gear sets with an integral clutch and bands to achieve separate gear ratios, the Xtronic CVT replaces those discrete gear ratios with an infinitely adjustable ratio design. Instead of using fixed gears, Xtronic CVT transmits power through two variable diameter pulleys and a high strength steel belt. The Xtronic CVT changes ratios smoothly and seamlessly with no perceptible pauses, jerks or lurches - virtually eliminating traditional shift shock.
During acceleration, the pulleys move in opposite directions and the steel belt rides on a smaller diameter, closer to the axis; when the pulleys are close, the steel belt rides on a larger diameter, near the outer rim. The pulleys are controlled to expand and contract in opposite directions so the ratio of the drive diameters between the two pulleys can be varied over a wide range, resulting in an infinitely variable drive ratio. The Xtronic CVT offers a spread of "gear" ratios between its lowest and highest range (2.371:1 to 0.439:1).
At the heart of the Xtronic CVT is a high-strength, flexible steel belt. The strength enables it to handle a high amount of torque input, fitting for Murano's V6 engine.
Xtronic CVT Benefits
Xtronic CVT brings a number of benefits that are immediately recognizable. The most obvious benefit is the quick response and smooth ratio changes, versus the clunk of a shifting transmission that is familiar to all drivers.
In contrast, the Xtronic CVT is nearly perfectly smooth it naturally changes gears discreetly and minutely such that the driver or passenger feels only steady acceleration.
Another advantage of the Xtronic CVT is its powerful driving performance. CVT offers the convenience of an automatic with the performance similar to a manual. Due to its pulley and chain design, Xtronic CVT can maintain the ideal ratio to keep the engine in its optimal power range.
This power is especially felt in mountainous driving ranges, as it can smoothly tailor the gearing to suit the hills, rather than constantly downshifting, searching for the appropriate gear.
The Xtronic CVT also allows for improved fuel economy. By varying the gear ratio continuously, the Xtronic CVT suffers no power loss during shifting allowing the engine to operate under conditions of optimum efficiency. Thanks to these remarkable features, a CVT can improve fuel economy by approximately 10% over a conventional automatic transmission.
Gearing
Incorporating a 6-speed manual shift mode, the XTRONIC CVT-M6 is a large-capacity steel-belt CVT, newly developed for use with a 3.5-liter engine. With its wider gear ratio range and expanded lockup operating area, the XTRONIC CVT-M6 combines smooth acceleration with improved fuel economy. Moreover, its 6-speed manual shift mode allows the pleasure of sporty driving.
| D position | Manual mode (*) | |
| Gear ratio 1st gear | 2.371-0.439 | 2.371 |
| Gear ratio 2nd gear | 1.530 | |
| Gear ratio 3rd gear | 1.110 | |
| Gear ratio 4th gear | 0.860 | |
| Gear ratio 5th gear | 0.690 | |
| Gear ratio 6th gear | 0.439 | |
| Gear ratio Reveres | 1.766 | |
| Final gear reduction ratio | 5.173 | |
- Typical gear ratios in each gear position in manual shift mode
Improved fuel economy
The wider gear ratio range and reduced friction work to improve both fuel economy and drivability performance.
Grade JK Japan's 10-15 mode fuel economy
- JK: 10.0km/L
- JM: 9.8km/L
Delivering smooth, pleasing performance in all sorts of driving situations
Vehicle response when climbing hills and coming out of turns has been improved over that of previous CVTs. Moreover, linear control provides drivability with a prefect match between the feeling of acceleration and the driver's sensibility.
When there is a series of uphill and downhill grades, the repeated shifting and braking operations required in vehicles with a conventional automatic transmission can be annoying. With the XTRONIC CVT-M6, there is no repetitive cycle of shifting on long uphill grades. In addition, this CVT also allows suitable engine braking on downhill grades for stable, smooth driving performance.
By suppressing the large engine flare-up that occurred with previous CVTs (1), the XTRONIC CVT-M6 shortens the interval to the peak longitudinal G, thereby eliminating any rubber-band feeling (2). In addition, it allows the engine speed to rise following a flare-up (3), instead remaining sluggish as it did with previous CVTs. That prevents any sharp decline in longitudinal G for a sustained feeling of acceleration (4).
