From the urban crawl to gridlocked motorways, the advantages of an automatic transmission are becoming increasingly appreciated in modern motoring.
Recent video productions for Auris and Yaris models have played on this fact, proving the likelihood of an improved relationship with driving when the car is able to shift gears automatically, even encouraging drivers to have a good sing-song.
Motorists are familiar with the continuously variable transmissions fitted to all Toyota models equipped with Hybrid Synergy Drive (Yaris, Auris, Prius, Prius +) but we have discovered that they are less acquainted with the automatic gearbox options for more traditionally-powered models. One of these is the popular Toyota Avensis.
The current Toyota Avensis is equipped with two automatic gearbox options: Multidrive S transmission on the 147bhp 1.8-litre Valvematic petrol engine, and a six-speed automatic paired with the powerful 150bhp 2.2-litre D-CAT diesel engine.
The former is a continuously variable transmission (CVT) from the K-series family designed to achieve both high fuel efficiency and powertrain performance through size and weight reductions that make it perfect for 1.5- to 1.8-litre engines.
Known internally by its ‘K311’ product code, the transmission shifts imperceptibly through an infinite number of gear ratios by using two cone-shaped pulleys and a high-strength V-shaped steel belt. Each gear is specifically chosen to help the engine work at its most efficient speed given the prevailing road conditions and throttle position. Control logic monitors the incline or decline of the vehicle and adjusts the transmission to either reduce the amount of gear shifting or make the best use of engine braking.
Unlike other CVT gearboxes, when the Avensis engine is pressed a little harder, the intelligent K311 simulates the behaviour of a seven-speed automatic, helping to minimise the characteristic whining associated with CVTs under hard acceleration. Those same seven gears can also be accessed in sequential manual mode, which lets the driver decide when to change gear by flicking the shift lever up and down in the M-gate.
Toyota’s aim for the K311 transmission was to set new standards for low noise and computer control software. While the control logic of other CVTs within the Toyota range, for example in the Prius range, have concentrated on fuel economy, Multidrive S adds an additional layer of driver involvement as well as reduced engine ‘flare’ during acceleration.
The six-speed automatic gearbox on the 2.2-litre D-CAT diesel Avensis is known by its ‘U660E’ product code and is one of the most recent additions to the acclaimed U-series transmission family. As such, it represents the pinnacle of Toyota’s Super ECT (Electronically Controlled Transmission) technology for front-wheel drive vehicles, which integrates the electronics of the gearbox with the engine’s own computer system. In other words, by sharing electronic data and adapting accordingly, Super ECT ensures that the engine and gearbox work together more efficiently, reliably and smoothly.
But there is much more to the U660E transmission than being able to understand binary code. Its inclusion of the world’s first ultra-flat torque converter means the gearbox is just 384mm long and has a wet weight of 94.5kg. It also incorporates high-precision yet low-friction oil flow management through an advanced electromagnetic linear solenoid.
As you can see from the flow diagram above, that control, together with precise information about vehicle and engine speed, throttle position, engine temperature and even the incline of the road, is used to improve shift quality, response time and fuel economy. Toyota has named this adaptability Artificial Intelligence Shift Control.
Though perfectly developed for stress-free driving, the U660E transmission also includes features that endear it to enthusiastic drivers. D-mode can be temporarily overriden with a flick of the ‘-‘ paddle on the steering wheel to prepare for overtaking or cornering, while a press of the Sport button triggers a more aggressive shift pattern in the AI-Shift Control programming.
In addition, a deliberate moving of the gear lever into the M-gate allows the driver to instruct gearchanges using the lever or paddles; super-fast downshifts being accompanied by a pleasing throttle blip. This manual mode provides lock-up in gears two through six and the transmission will hold on to each ratio right up to the red line.
So whether you prefer petrol or diesel power, CVT or a traditional automatic gearbox, the Toyota Avensis offers a balance between responsiveness, smoothness and, of course, fuel efficiency.