Fresher to the range is a sub-100g/km 1.6-litre oil-burner, the poster child for Honda's latest, frugal engine range. It has replaced the larger capacity all-aluminium 2.2 i-DTEC unit.
The smaller 1.6-litre turbodiesel's 118bhp of peak power and 221lb ft of torque, combined with CO2 emissions of 94g/km, make it an outstanding on-paper prospect among its peers.
As is the class norm, the engine sits transversely under the bonnet and drives the front wheels through a standard six-speed manual gearbox. As with the outgoing Civic, suspension is via MacPherson struts at the front and a torsion beam at the rear.
The smaller diesel is pleasingly unaffected by the usual rattle and clatter of diesel engines at low and middling crank speeds, and pulls as hard as many 2.0-litre units at times.
It doesn’t like revving beyond 3500rpm too much, and isn’t as refined at high revs as it is lower down. But throttle response is good, and there’s no sense at all that what you’re driving might be in any way austerity-minded.
The 1.6-litre diesel engine is very effectively isolated from the cabin, too. Honda makes a big deal of the noise and vibration reduction regime that the Civic has been through. This has resulted in extra insulation in the rear wheel arches, roof and engine bay, better door seals all round and thicker front side windows.
You can certainly perceive the improvement. Although the noise levels we recorded look quite average, they mask a car that filters out the harshest frequencies of mechanical noise and road roar very well, and it suffers with little wind rustle.
Both the naturally aspirated 1.4-litre and 1.8-litre petrol engines are a little outclassed in terms of their figures and overall usability by the more refined turbocharged petrols available in rival cars.
The 1.8-litre petrol engine is a mixed bag. Around town and at a cruise it’s a model of smooth, hushed refinement, but it isn’t particularly satisfying to work hard.
Peak torque – and it is a peak, not a broad spread – of just 128lb ft appears up at 4300rpm, and consequently the 140bhp peak power figure appears high up, too, at a lofty 6500rpm.
Add long, widely spaced upper gear ratios, presumably to help lower the CO2 figure, and the perverse consequence is that you have to rev the high heavens out of it on wide throttle openings to make the car feel reasonable sprightly, which results in anything but low CO2 figures.
It also results in quite a bit of noise in the cabin and the need to shuffle up and down the gearbox to maintain speed – and in the 1.4-litre petrol, even more so.
A six-speed manual gearbox is the default option across all the variants, although the 1.8-litre petrol can be specified with a five-speed automatic transmission. In that form the Civic returns a claimed 44.8mpg and emits 148g/km of CO2.