| “Quite
simply the smoothest three-cylinder
engine that I’ve ever experienced”
Jake Venter, CAR, South Africa
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In 2007, the honour in the Sub 1-litre
category at the International Engine of the Year Awards goes
to the Toyota 1-litre three-cylinder petrol engine found in
the Aygo/Citroën C1/Peugeot 107 triplets, plus the Yaris/Echo/Vitz.
The Toyota 1-litre is said to be the
lightest internal combustion engine
on sale today. Weighing 69kg, its
designers employed an all-aluminium construction and made the
throttle
body and fuel pipe out of resin instead
of metal. Meanwhile an extra-small
cylinder bore-to-bore distance makes
for a very compact engine block – the wall thickness between
the bores is
just 7mm, thinner than on any other Toyota engine – and
the air intake
system and engine cover are integrated into a single unit, a
design first for the Japanese firm.
With 67bhp and 93Nm at 3,600rpm, the engine has impressive power
and
torque for a 1-litre. And with a potential 4.6L/100km (61.4mpg),
the powerplant also has the lowest combined cycle
fuel consumption for a petrol engine
in its segment.
Key to achieving these figures is the adoption of VVT-i variable
valve timing, which Toyota says is the most advanced such system
in the segment. In addition, a new resin coating for the pistons,
thin, low-tension piston rings and the three-cylinder configuration
all contribute to the decrease in friction losses.
Judge Ken Gibson from The Sun
newspaper in the UK described the engine as, “A modern
engine for the
real world. It may only be a 1-litre but
this engine has real character, surprising performance and great
economy.” |
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