What is the detailed explanation of Aisin's third-generation 6AT?
4 Answers
The third-generation Aisin 6AT transmission utilizes two sets of planetary gears, which effectively reduces fuel consumption during upshifts. It expands the lock-up range, further contributing to improved fuel efficiency. The energy-saving valve body has been upgraded to a high-performance, low-power consumption version, allowing for adjustable flow rates during idle start-stop operations. Below are the key features: 1. Enhanced fuel efficiency: The oil pump has been upgraded to an electronically controlled system, reportedly improving fuel efficiency by 9% alone. Additionally, this transmission can use low-viscosity transmission fluid, reducing churning resistance during gear shifts for better fuel economy. 2. Quiet operation: A long-stroke damper has been incorporated into the torque converter to suppress vibrations. With smooth gear shifts and a wide gear ratio range, the 6AT helps maintain lower engine speeds, naturally resulting in reduced noise levels.
I've been a master technician at an auto repair shop for over a decade, having worked on hundreds of vehicles equipped with Aisin's 6AT transmission. The third-generation core feature is an expanded torque converter lock-up range reaching 85%, which can engage at just 40 km/h, making it 8% more fuel-efficient than the second generation. The planetary gear set incorporates a new angle design, reducing shift shock to nearly imperceptible levels. The most practical feature is the neutral coasting mode – it automatically shifts to N when you lift off the throttle, lowering RPM for fuel savings. However, I must remind everyone: you must use genuine ATF fluid at 60,000 km intervals, as mixing fluids can cause solenoid valve sticking. This transmission performs exceptionally well in older Lexus ES models, with many examples running over 300,000 km without major repairs.
Last test drive of the Corolla 1.8L was equipped with this gearbox, here's the driving feel. Light throttle downshifts are slightly slower than VW's DSG, but aggressive acceleration delivers satisfying two-gear drops with strong burst power. In D mode at red lights, the transmission disengages completely - vibrations are much reduced compared to old Toyota 4AT. Sport mode is interesting, holding gears until 4000rpm to simulate manual transmission tugging sensation. Found a trick: manually locking in 2nd gear uphill is much smoother than D mode's frequent gear hunting. Minor complaint: occasional cold-start 1-2 shift clunk that disappears when warm - common characteristic with no fix.
From technical specifications: The gear ratio span is 6.5, with 1st gear at 4.17 capable of climbing a 35° slope, and 6th gear at 0.69 ratio running at 2000 RPM for 120km/h. The entire series integrates an oil heater, enabling cold starts at -30°C with heating speeds three times faster. The valve body utilizes dual linear solenoid valves, increasing shift speed by 40%. Its flexible lock-up clutch is particularly impressive, offering CVT-like smoothness during semi-engagement. However, real-world urban fuel consumption is about 0.5L higher than Mazda's 6AT, attributable to the additional mechanical losses from an extra set of planetary gears.
