Diesel power/torque outputs have steadily increased since the non-turbo days - a 1.6 is probably more economical than a 1.8 or 2.0 and if it now has enough power to do the job, then it's an obvious way to go.

120bhp and 300Nm is quite respectable.

probably for 2 reasons that I can think of:

1 - Generally more economical on fuel

2 - Cheaper to run, less tax (lower CO2), less insurance

Essentially - people are downsizing and looking at reducing their running costs

As mentioned above, perhaps around 400cc per cylinder is an optimum for thermal efficiency given the new world of DPFs etc. The issue engine designers face these days is that they have to start their designs at the end of the exhaust tailpipe.

Oddly, my Volvo D3 is a 2 litre 5-pot, giving approx 400cc per cylinder. Unusually for a diesel, it's also oversquare (short stroke). However, it goes like ordure from a digging implement and has averaged a genuine 46mpg since new, so it all works nicely ...

The last two posts are homing in on my own thoughts, is it an optimium cylinder size for diesel combustion, but factored with the minimium number of cylinders for reasonable smoothness, i.e. 4 No, but then if one requires 4 cylinders and a 1600 cc engine is now more than capable of developing the necessary torque & horsepower.

End of storey.

I do realize that lorry (truck) engines are usually only 6 cylinder but 12, 13 or 14 litre.

Or for that matter a super efficient "diesel" for supertankers still only has a limited number of VERY large cylinders, so that kinda scotchs the 400cc per cyl theory

gibber

mutter

& twitch