Hybrid Still Toyota’s Top Choice for New Yaris

Toyota is staking its hybrid reputation on the latest generation of its top-selling compact urban car, the new Yaris.

The car, unveiled to the European media this week, employs the automaker’s fourth-generation hybrid electric powertrain claiming less weight to aid fuel economy and reduce emissions efficiency, while boasting increased power and torque. Engineers have specifically tuned its chassis and powertrain to suit European roads and claim their data gathered has allowed for its overall efficiency to be increased by 20%.

Despite the fuel and emissions savings, Toyota claims 1 16% boost in power up to a total of 113bhp with a 15% improvement in 0-62mph acceleration now at 9.7 seconds. It’s all electric abilities have also been boosted claiming to be able to reach an EV only top speed of 80mph and longer emission-free driving in urban environments.

Its CO2 emissions have dropped to 85 g/km and the WLTP combined cycle fuel economy figure is stated at 104mpg (87mpg US). At the same time, engineers focused on the highway overtaking performance, considered a weak point on previous models, cutting the 50mph to 75mph sprint time byt two seconds to 8.1 seconds.

The powertrain sees the introduction of the first 1.5-liter gasoline ‘Hybrid Dynamic Force Engine’ developed from the same TNGA engine family as the 2.0-liter four-cylinder unit featured in the Toyota Corolla and C-HR. It has a long stroke, 14.0:1 compression ratio and high-speed combustion with improved temperature and pressure control.

This three-cylinder unit has a maximum output of 90bhp with a peak 88ft-lbs of torque of delivered at 3,600 rpm. Transmission is a e-CVT automatic – an electric continuously variable transmission.

Its hybrid system has two motor/generators, with one linked to the front wheels and can be used as the power source to drive the vehicle. The second is deployed to start the engine and to generate power to charge the battery.

Voltage of its lithium-ion hybrid battery has been upped from 144 to 177.6 V while the number of cells has been reduced, from 120 to 48. This claims that current flow is improved by 100% into the battery and 50% out. With a higher power density, the battery is both smaller and lighter, by 12 kg, allowing it to be located beneath the rear passenger seat, together with the auxiliary battery.

It also boasts a new hybrid transaxle which is more compact and lightweight, having the two motor generators placed on multiple shafts instead of being placed one behind the other, so reducing the unit’s width by around 1.5 inches. Motor/Generator 2 benefits from new segment-type coils on the stator, which makes the unit more compact. It can deliver 23bhp and 103ft-bs of torque to the front wheels at a maximum 17,000 rpm.

Despite the push for electrification, Toyota will still offer pure ICE alternatives including  the new 1.5-liter gasoline engine with six-speed manual or continuously variable transmission (W-CVT). While, in certain markets, a 1.0-liter three-cylinder gasoline engine, similar to the one featured in the previous-generation Yaris, is available as an entry point to the range.

— Paul Myles is a seasoned automotive journalist based in London. Follow him on Twitter @Paulmyles_


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