Yaris dpl 2011: Efficient engines and innovative transmission

Continuing the successful mix of powertrains featured in the previous generation model range, the new Yaris will be available with a choice of three engines 1.0 and 1.33 litre VVT-i petrol engines and a 1.4 litre D-4D turbodiesel.

The 1.33 litre petrol unit may be mated to Toyota's latest Continuously Variable Transmission (CVT), Multidrive S, while an automated manual transmission, MultiMode, is available as an option on 1.4 D-4D diesel versions of the new Yaris.

All three engines benefit from the application of Toyota Optimal Drive, a range of engineering measures designed to maximise performance and driving enjoyment while minimising fuel consumption and CO₂ emissions.

Toyota Optimal Drive focuses on several key aspects of powertrain development such as lightweight, compact design, enhanced combustion efficiency, low friction components and environmentally friendly technologies. This, combined with weight saving measures and aerodynamic improvements, helps lower fuel consumption and CO₂ emissions without compromising power and torque levels.

Combining light weight and compact design with the power and torque delivery essential to urban driving, all three engines return highly competitive fuel consumption figures, generate low, tax-efficient CO₂ emissions and are Euro V compliant.

1.0 Litre VVT-i petrol engine

A marvel of miniaturisation, Toyota's 3-cylinder, 1.0 litre VVT-i petrol engine led the trend for powertrain downsizing. To this day, it remains a reference for compact, efficient engineering. The lightest unit in its class, it has won successive Engine of the Year awards in the sub-1.0 litre category.

Mated to a 5-speed manual transmission, the latest version of the 998 cc unit generates 51 kW/ 69 DIN hp at 6,000 rpm and maximum torque of 93 Nm at 3,600 rpm. Fuel consumption has been lowered by 4% to a class-leading 4.8 l/100 km, and CO₂ emissions have fallen by 7% to 110 g/km.

The 1.0 litre petrol engine is produced in Europe, at Toyota Motor Manufacturing Poland.

1.33 Litre Dual VVT-i petrol engine

The 1.33 litre petrol engine is equipped with dual VVT-i (Variable Valve Timing-intelligent), Exhaust Gas Recirculation (EGR) and a remarkably high compression ratio of 11.5:1. Mated to a 6-speed manual transmission, it generates 73 kW/ 99 DIN hp at 6,000 rpm and maximum torque of 125 Nm at 4,000 rpm. With a smoothened torque curve, the unit combines strong dynamic performance with fuel economy of just 5.1 l/100 km and CO₂ emissions of only 118 g/km, when combined with the Multidrive S transmission.

The engine unit is lightweight and compact, with a small bore and long stroke, resulting in a very high power-to-weight ratio. It features a resin-type cylinder head cover and intake manifold, and the intake channel has been streamlined to optimise airflow for improved combustion efficiency.

The adoption of camshaft roller rocker arms, a highly compact oil pump and a reduction in the number of ribs on the auxiliary belt helps minimise engine friction losses, hence improving fuel economy. And control of the Dual VVT-i and EGR systems has been integrated to further enhance combustion efficiency.

Dual VVT-i helps boost response levels across the entire rev range by varying the air-fuel intake and exhaust valve timing to suit the conditions at any given time. In addition to improving torque at low and medium engine speeds, the system also reduces emissions.

EGR reintroduces precise amounts of cooled exhaust gas into the intake system. This not only reduces engine pumping loses through a reduction in intake vacuum pressure, but also lowers engine operating temperatures by 40˚C to minimise the situations where fuel enrichment is necessary to protect the catalytic converter from overheating damage.

Multidrive S transmission

The 1.33 litre petrol engine's optional Multidrive S transmission showcases Toyota's latest Continuously Variable Transmission (CVT) technology. It features a manual override, sequential, 7-step mode operable by either the gearshift lever or steering wheel-mounted paddles.

This compact, lightweight CVT system is one of the most fuel efficient automatic transmission in the B-segment petrol, returning 5.1 l/100km.

Multidrive S operates within a wider band of gear ratios than a conventional transmission, allowing for both better acceleration from a standstill and improved fuel efficiency at cruising speeds. Its advanced control systems incorporate Flex Lock-up Control, Flex Start Control, Lock-up Slip Control and Speed Ratio Control to maximise fuel efficiency, minimise noise and enhance the driving experience.

Flex Lock-up Control continuously adjusts the degree of lock-up within the torque converter. This control function optimises the transmission's balance of torque delivery and fuel economy. It allows the engine to deliver the greatest fuel efficiency, whilst minimising vibration at even low vehicle speeds.

When pulling away from a standstill, Flex Start Control lowers the vehicle speed at which torque converter lock-up is possible from 15 to just 10 kilometres per hour. This minimizes torque waste, producing optimum acceleration from lower engine revs for improved fuel economy.

When coasting and under deceleration, Lock-up Slip Control enhances freewheeling efficiency through an expansion of fuel shut off duration. When the vehicle is stationary in D-mode, a neutral control will temporally disengage the transmission from the engine to minimise idling fuel consumption.

The CVT's Speed Ratio Control incorporates a number of systems to not only further improve fuel efficiency but also enhance the driving experience. Uphill/downhill shift control uses information from various vehicle sensors to determine whether the Yaris is travelling up- or downhill. When travelling uphill, speed ratio changes are restricted to achieve smooth operation. If brake pedal use is detected when travelling downhill, the speed ratio is automatically changed to provide appropriate engine braking force.

Engaging the Multidrive S Sport mode brings a closer alignment of engine and vehicle speeds, giving a more linear feel to acceleration in the manner of a conventional manual transmission. The Sport mode enhances acceleration performance and awards the driver a more dynamic driving experience.

Stop & Start system 

Yaris models fitted with the 1.33 litre Dual VVT-i petrol engine may be equipped with an improved version of Toyota's Stop & Start system. The system may be used in conjunction with the optional Multidrive S transmission, delivering fuel consumption of 5.0 l/100km and CO₂ emissions of only 114 g/km.

Featuring an immediate restart with virtually no engine sound or vibration, the system delivers significant reductions on CO₂ emissions during urban driving, and can lower fuel consumption by up to 10%, depending on driving conditions.

Stop & Start automatically stops the engine when the car is stationary, and the clutch pedal —or brake pedal in the case of Multidrive S- is pressed. The engine will automatically restart, within less than half a second, when the same pedal is released.

The system's rapid restart is made possible through the use of the world's first permanently engaged gear mechanism in which the starter motor and flywheel are linked, via a ring gear, by a one way clutch. This high power, maintenance-free system reduces engine start noise levels within the cabin, and seat vibration levels.

A back-up boost converter is incorporated to protect the audio system, meters and ECUs (Electronic Control Units) from a voltage drop caused by the electrical load of the starter motor. The converter boosts the voltage supplied to accessories in compensation for the power consumed by the starter motor.

Now able to function in outside temperatures as low as -15˚C, Toyota's Stop & Start technology also allows for the continued operation of the air-conditioning system. With the air-conditioning in use, the engine will not stop if the desired cabin temperature has not been reached. When that temperature has been reached, the air-conditioner will switch to 'ECO-run', allowing the engine to stop.

The Yaris' improved Stop & Start system has been optimised to allow the engine to remain off for up to half a minute longer than that of its predecessor, even with the air conditioning running. The engine will automatically restart in the event of low battery charge, or if the vehicle begins to move, in the interests of safety.

1.4 Litre D-4D diesel engine

The 1.4-litre D-4D common rail, intercooled turbodiesel employs the latest piezo-electric technology and is equipped, as standard, with a Diesel Particulate Filter (DPF). Equipped with a 6-speed manual transmission, it generates 66 kW / 90 DIN hp at 3,800 rpm and maximum torque of 205 Nm at 1,800-2,800 rpm.

Benefiting from high injection pressure of 160 MPa, the piezo-electric injectors can supply larger, more precise volumes of diesel at twice the speed of conventional fuel injectors. Because of their high operating speed, they can deliver multiple injections per combustion cycle, optimising the combustion process for responsive performance, enhanced fuel efficiency and reduced emissions.

The latest version of this durable, reliable diesel engine is equipped with a two-stage oil pressure control system and an LLC (Long-Life Coolant) by-pass system to reduce circulation flow rate under cold conditions, improving warm-up performance and, hence, fuel efficiency. As a result, fuel economy has been lowered by 7% to only 3.9 l/100 km, and CO2 emissions have reduced by 6% to just 103 g/km.

MultiMode transmission 

Available as an option on 1.4 D-4D diesel versions of the new Yaris, MultiMode is an automated manual transmission with a fully automatic shift mode and no clutch pedal. It offers the driver a choice of two, fully automatic gear change modes or a manual, sequential gear change with steering wheel-mounted shift paddles. When equipped with MultiMode transmission, the 1.4 D-4D Yaris returns fuel consumption of 4.0 l/100km and generates CO₂ emissions of 105 g/km.

Selecting E (Easy), M (Manual) or R (Reverse) allows the car to 'creep' in the manner of a conventional automatic. In E mode, the car makes automatic gear shifts that will maximise fuel economy. Selecting ES (Easy Sport) mode will delay changing up to a higher rpm, giving a more sporting style of drive.

Eco Driving and Gear Shift Indicators

An Eco Driving Indicator is included in the instrument binnacle of Yaris models equipped with Multidrive S transmission, helping drivers to realise an eco-friendly, low emission-style of motoring. Under Eco driving, the Eco Driving Indicator light will illuminate during accelerator operation in the most fuel efficient zone. When the use of the accelerator exceeds this zone, the Eco light goes out.

On manual models, a Gear Shift Indicator prompts the Yaris driver to shift up or down a gear for maximum fuel efficiency. Monitoring driving conditions, vehicle speed and throttle inputs, the system can help reduce fuel consumption by 0.5-3.0%, depending on driving styles.