Mazda MX-5 2018 Review – Australia

Ask anyone about the Mazda MX-5 and there’s always a ‘but’.

“Yes, it’s a terrific handling car, but…” or, “I’d have one in a heartbeat, but…” And that ‘but’ is almost always followed by “it needs more power”.

Mazda has heard those qualifiers.

The manufacturer has now upped the output of both the 1.5 and 2.0-litre versions of its popular MX-5 Roadster and Retractable Fastback variants. For the single-variant Roadster with 1.5-litre power that’s a modest increase of 1kW/2Nm for a total of 97kW/152Nm, while the remaining 2.0-litre powered models jump 17kW/5Nm to produce 135kW/205Nm. ‘But’, the numbers only tell part of the story.

Changing the characteristics of the engine – specifically the 2.0-litre SKYACTIV-G – has gifted the MX-5 with not only more power, but more useable power. Power where it counts.

The willingness to rev faster to its increased rev ceiling of 7500rpm gives the 2.0-litre engine an at-the-limit playfulness previously only found in the 1.5-litre powered models.

Full power arrives 1000rpm later, now 7000rpm, but also presents itself more quickly (i.e. it revs up faster), the slight but collectively significant changes to intake, exhaust, cylinder head, cams, crank and ECU (more details below) producing a rounder impulse band better suited to the MX-5’s fun-to-drive character.

Gone is the ‘hard cut’ at 6800rpm, so too the narrow torque curve that kept the six-speed gearbox busy. That beefier torque curve means the car is more driveable at fair to middling speeds, the availability of 205Nm some 600rpm earlier (now 4000rpm) bettering the drive out of corners and off-the-line acceleration.

Making sure driving enjoyment continues to headline the MX-5 story means evolving a formula with narrow constructs. The MX-5 has never been about ‘big power’. It’s a car that’s about enjoyment at the wheel, about offering spirited performance without the excess of grunt we often feel we need, but rarely ever use.

And while this is the most powerful normally-aspirated MX-5 Mazda has ever produced, it isn’t the highest performing example it’s sold. That honour goes to the Australian-developed MX-5 SP, with a Garret turbocharger raising output to 157kW/289Nm – or 44kW/108Nm more than the second-generation NB-series derivative; and paving the way for the factory-backed 121kW/206Nm turbocharged model dubbed MX-5 SE (also Mazdaspeed or Roadster Turbo depending on market) which sold globally from 2004 to 2005.

But rather than force-feeding the already highly strung 2.0-litre SKYACTIV mill, Mazda set to fine-tuning the unit’s inner workings in a manner reminiscent of the ‘blueprinted’ update to the previously generation NC2-series circa 2008. As one of our contributors puts it: “making the bits that go up and down lighter so that they can go up and down faster”.

The improvements include a freer flowing intake and exhaust systems, a revised combustion chamber with larger exhaust ports and valves, taller cam profile, shorter intake manifold, lighter pistons (-27g) and connecting rods (-41g), repositioned crankshaft counterweights and a remapped ECU. The throttle body now measures the same diameter as that found on Mazda’s 2.5-litre SKYACTIV-G engine (+18 per cent).

Manual models score a low-inertia, dual-mass flywheel in place of the single-mass unit while automatic variants see a reduction in final drive ratio from 3.454 to 3.583:1.

Fuel consumption falls 0.1 and 0.2L/100km to 6.9 and 7.2L/100km for six-speed manual and six-speed automatic variants respectively.

Changes to the 1.5-litre model are trivial by comparison, Mazda saying the slow-selling model’s “target characteristics have already been achieved”. Newly shaped common-type intake ports, a lower piston crown height (with step-shaped upper rim), and high-diffusion fuel injectors with three-stage (direct) injection process add 1kW/2Nm, but the automatic variant does not receive the same final drive ratio change as the 2.0-litre model.

Fuel consumption for the 1.5-litre SKYACTIV-G engine is listed at 6.2 and 6.4L/100km for six-speed manual and automatic models respectively, an increase of 0.1L/100km for manual models [automatic models are unchanged].

With the techy stuff out of the way it’s time to look at the other changes to the fourth-generation MX-5. Based on owner feedback, Mazda has added a tilt and reach adjustable steering column, new sunvisors, thicker seat recline levers, more rigid inner seat frames and a two-stage door checker to improve open and closing feel. It’s even beefed-up the detachable cup-holders – a more rigid design reduces “wobble” and improves attachment and removal action.

Minor steering and suspension changes from the previous update are carried over while a new reversing camera is said to provide a sharper image for Mazda’s now-standard MZD Connect infotainment system and 7.0-inch colour display – except it’s really pretty low-res.

The exhaust note is also said to be improved – if anything it’s a little ‘richer’ in pitch – while black metallic-painted 16-inch alloy wheels feature on the 1.5-litre Roadster (previously silver) and 17-inch black-paint alloys are standard on the 2.0-litre RF (previously gun metal grey).

Importantly, low-speed autonomous emergency braking (or Smart City Brake Support in Mazda parlance) is now standard across the range. It’s backed by reverse brake support on GT variants, and driver fatigue detection and traffic sign recognition. The MX-5 scored a five-star ANCAP rating when last crash tested in 2016.

Mazda’s newly announced five-year/unlimited kilometre warranty is also included, but is not backed by roadside assistance (which remains a cost option) or capped-price servicing. Mazda does, however, advertise the price of its log book services on its website, the MX-5 requiring a visit to the service department every 12 months or 10,000km (whichever comes first).

Besides the small increases to throttle-on response at corner exit and obviously brisker straight-line acceleration the MX-5 remains true to form. The added power hasn’t diminished the car’s wonderfully fluid handling, and unlike turbocharged power it's not brusque in its delivery. In short, the changes work with the driver to enhance the experience at the wheel – just the way it ought to be.

Best of all the performance improvements are noticeable in everyday and at-the-limit driving. And while it doesn’t match competitors like the Toybaru 86/BRZ for power (152kW/212Nm), or the Abarth 124 Spider for torque (125kW/250Nm), the added urge has improved the MX-5 as a driver’s car – which I think is what those asking for more power had really always wanted. More is better? You better believe it.

How much does the 2018 Mazda MX-5 1.5-litre SKYACTIV-G cost?
Price: from $34,190 (plus on-road costs)
Engine: 1.5-litre four-cylinder petrol
Output: 97kW/152Nm
Transmission: Six-speed manual; six-speed automatic
Fuel: 6.2; 6.4L/100km (ADR Combined)
CO2: TBA
Safety Rating: Five-star ANCAP (2016)

How much does the 2018 Mazda MX-5 2.0-litre SKYACTIV-G cost?
Price: from $39,400 (plus on-road costs)
Engine: 2.0-litre four-cylinder petrol
Output: 135kW/205Nm
Transmission: Six-speed manual; six-speed automatic
Fuel: 6.9; 7.2L/100km (ADR Combined)
CO2: TBA
Safety Rating: Five-star ANCAP (2016)