We like
Bountiful low and mid-range response, fuel economy, smoothness, comfort

Room for improvement
Thick A-pillars, torque steer, road noise

DIESEL technology has made huge strides, but not all new-age diesels have made great advances over diesels of old. Some still wheeze and smoke too much, are too noisy and bi-polar in their power delivery – depressed off the mark and manic in the mid-range.

The Mazda3 Diesel is not such a vehicle. This engine is an absolute corker.

The Mazda3 Diesel starts immediately and – even better – settles into an almost silent, smooth idle. Only those with ears attuned to the distinctive diesel rattle will pick it up. For anyone else, they will never know this car is powered by distillate at idle.

To get going, barely any throttle input required, and response feels instant, except for a momentary hesitation as the turbo spools up. So yes, it has turbo lag but not much of it.

Once the tacho needle swings towards the 1800rpm peak torque mark, it all starts to happen. Throttle response is so crisp at this point that in most situations the driver barely needs to squeeze the pedal, easily keeping up with the traffic by short shifting, never exceeding 2000rpm.

Forget to change down a gear and the engine will not complain. It will usually just lug along and ease itself up the rev range as you apply throttle.

If you do want to make a lunge for a traffic gap, instant acceleration is available aplenty. The engine does not have to be worked to get big results.

Even in sixth gear at 1800rpm on the freeway, the response is admirable. Not many highway hills will necessitate a downshift if you are able to keep speed above about 90km/h.

The engine will rev out to 5200rpm, but there is no point going much past 4000rpm, as the tacho’s quick flick towards the redline begins to slow. This is all about using the torque band low in the rev range.

The only issue with the immense torque on tap is that on uneven surfaces, torque steer can get a little unruly. It will not wrench the steering wheel from your hands, but can take you by surprise, especially given its total absence when accelerating hard on smoother surfaces.

Fuel economy is thrifty, although it pays to take a realistic view of how thirsty a diesel can be if you are one of those people who do plenty of short trips in congested urban areas even diesels will use more fuel.

Driving in peak hour traffic for most of the week, we found fuel consumption settling around 9.0L/100km. When we included open road running, the fuel consumption figure dropped to 7.0L/100km, and purely highway cruising achieved a figure of 4.8L/100km.

The Mazda3 Diesel’s steering is has the right balance of weighting, feel and response to input.

This ties well with a chassis that tackles corners with a flat stance and planted, stable feel. The ride is a little terse and noisy over lumpy city roads, but otherwise absorbs the sharpest of bumps that many cars typically crash through.

Speaking of noise, the reflected road noise is not as bad as it used to be, but it is still the main source of noise in the Mazda3, and it’s particularly obvious as wind and engine noise are so well suppressed.

The Mazda3’s cabin is a quality space with loads of well screwed together, well-made components, up front at least. The front seats are supportive and have the right degree of firmness to keep occupants comfortable over long journeys.

The instruments are really well thought out, with everything up high so the driver is not left fumbling for buttons or wands and you can see the instruments with your eyes barely leaving the road.

The standard satnav screen is on the small side, giving only the name of the street. However, for a standard inclusion at this price point, it is still a good effort, and provided you can trust the route guidance alone, it is fine.

The gear lever is close to hand, providing a positive shift feel, and although the handbrake is next to the passenger, this is one of the few indiscretion in the layout of otherwise orderly controls.

Up front, the Mazda3 feels up-market, but less so down the back. The rear seat area lacks air vents, has a centre console that impedes centre occupant knee room, and the centre seat itself is quite uncomfortable, with a convex contour and hard padding.

The outboard positions are far more comfortable and roomy, but storage is lacking with cup holders in the doors, one pocket in the back of the left seat and two cup holders in the fold-down armrest.

Three child seat tether points are fitted under flip-up covers. They must be among the easiest to use.

The boot of the sedan we drove has a relatively wide opening and is a useful squared-off space, but the opening lip could be lower.

It also has cheap-looking carpet. An 80km/h-restricted space-saver spare tyre rests under the floor, and there are no tie-downs or storage cubby-holes.

The tall boot lid of the sedan makes it easy to see the back of the car when reversing, but parallel parking still requires much guesswork. It would be nice if parking sensors were standard.

The A-pillars are wide, impeding side vision, but the side rear-view mirrors are a good size.

The Mazda 3 Diesel is testimony to all the good reasons and none of the poor excuses for buying a small diesel car. While it costs more than the equivalent Mazda3 petrol variant, the immensely smooth and punchy performance is well worth it.

And no one complains about using less fuel these days - certainly not at the meagre rate the Mazda3 Diesel sips it.