Super Efficient Corolla Engine !!

Toyota's "Optimal Drive Technology" – released in Europe only three months ago – is now on the road in South Africa in a new 1.3-litre engine that replaces the previous entry-level 1.4-litre unit in the Corolla range.

It's not so much a new idea as a package of weight and friction-reducing techniques blended with some racing tweaks to produce a light, compact and fuel-efficient engine.

Toyota's slide-rule samurai started by reversing the current "oversquare" trend and going back to an old-fashioned long-stroke (72.5 x 80.5mm) configuration, which enabled them to build a 1.3-litre, four-cylinder engine 54mm shorter, 127mm narrower and 13kg lighter than the 1.4 it replaces – in fact it's the same size as the one-litre, three-cylinder engine in the Yaris.

The weight of each piston has been reduced from 280 to180g, piston skirt area and ring tension reduced to cut friction and the crankshaft offset so the con-rod is vertical when combustion chamber pressure is at its highest.

Computer simulations found the smoothest intake airflow with all surfaces smoothed and angles rounded – racing tuners would call it a gas-flowed head – and the combustion chambers have improved combustion efficiency.

Thin, long-reach iridium spark plugs and stick coils help make the cylinder head more compact. Variable valve timing on both camshafts improves torque spread and roller rocker arms reduce valve-train friction.

Toyota quotes 74kW at 6000rpm (a four percent improvement on the previous 1.4) and 132 Nm at 3800rpm. CO2 emissions, it says, are down from 158 to 138g/km and average fuel consumption from 6.7 to 5.9 litres/100km.

The six-speed manual gearbox has also been reduced in size and weight with smaller casings and a hollow output shaft.