Engine and gearbox
In the UK, the 6 is available with three engines made up of two naturally aspirated petrols and a single turbo diesel. All are four-cylinder Skyactiv units, the petrol models incorporating a combination of an extremely high compression ratio (14.0.1 if you were curious) and specialised low-friction internals. Mazda’s adherence to natural aspiration in its petrol engines is not an example of being behind the popularity curve, either, rather a different approach to the challenge of reducing CO2 emissions.
The entry-level 2-litre four-cylinder is available in two states of tune: 143bhp and 163bhp. The engine itself is a sweet little unit, revving with an enthusiasm and never sounding strained or harsh. Its similarities to the raspy unit found under the bonnet of the MX-5 are clear, and you end up using the engine in much the same manner. It does need to rev, but this is no chore as the excellent six-speed manual gearbox perfectly complements the engine. Pick up is clean, throttle response is as sharp as you could reasonably expect from a car of this type, while the throaty, albeit muted bark just adds to the fun.
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It’s not what you might call fast, though, and although there is plenty of shove when you wind it up, spur of the moment power requirements, like overtaking, can be a problem if you’re not paying attention. We didn’t get a chance to sample the lower-powered 2-litre, although we expect it might be the wrong side of slow for a car of this size, although it does produce the same 157lb ft torque figure, so will only be noticeably slower at the upper reaches of its rev-band. An automatic gearbox is also a no-go on the 2-litre, you’ll need to upgrade to the flagship 2.5-litre GT Sport model for that.
The top-spec 2.5-litre four-cylinder engine instantly feels better endowed. Its 190lb ft of torque is available lower down in the rev range, but it still needs to be worked to get the best from it. Power is also up to 191bhp, but there is a caveat or two with the larger power unit. The larger unit doesn’t rev quite as enthusiastically as the 2-litre, something only compounded by the fact it’s also only available with the six-speed automatic gearbox. Although not a bad gearbox in its own right, it’s rather good in fact, the combination of the two elements seems to lessen the Mazda’s perky, fun to drive nature, a unique selling point against many rivals.
This notion is compounded further in diesel-engined versions, too. The Skyactiv-D diesel engine is itself a pretty cutting-edge unit, with Mazda focusing on reducing the compression ratio to an identical 14.0.1 as the petrol. This low figure makes the Mazda’s diesel one of the cleanest, even meeting Euro6 emissions regulations without the need for any after-treatment, or more specifically the very thing that got VW into so much trouble with dieselgate. Still, if you’re the sort that does endless motorway runs, the diesel’s impressive MPG figure will make it impossible to overlook. If you’re into driving, though, it’s best overlooked.