The Japanese car maker Toyata has development of two hyper-fuel-efficient small-displacement petrol Atkinson cycle engines: a three-cylinder 1.0-liter and four-cylinder 1.3-liter. The engine is being brought to the market in an impressive 14 different formats. the smallest of them all being promised the one who will deliver the 78 mpg (US) in the Toyota Aygo. The amount of changes and upgrades are made.
A higher 11.5:1 compression ratio, an improved combustion chamber design, reduced frictional losses and a weight reduction courtesy of a cylinder head with a built-in exhaust manifold. All these tweaks has made the engine to have a fuel economy that has been reduced to 3.9 l/100 km (60 mpg US) at the same time as more power (68bhp – 51kW @ 6,000rpm) and more torque (95Nm @ 4,300rpm). Many new brilliabt innovation has been incorporated in the Atkinson engines.
They include a reshaped intake port designed to generate a strong tumble flow (whereby the air-fuel mixture flows in a vertical swirl) inside the cylinder, and a cooled Exhaust Gas Recirculation (EGR) system, Toyota’s Variable Valve Timing intelligent Electric (VVT-iE) technology, an idling-stop function, high compression ratio and various unnamed fuel consumption reduction technologies. the engines hence are lookin very promising.