Revamped 2.0-litre engine adds both sweetness and spice
Iconic sportscar gets power boost and attitude adjustment
THE YELLOW advisory signs with the squiggly lines provide the official confirmation of what we already know. We’re deep in Gold Coast drivers’ country, but still the lumbering Hilux in front of us holds his course. The lush hinterland ramps up towards Mount Tamborine, beckoning us in. Still we wait. Finally, mercifully, old mate sticks two wheels on the verge and allows us space to pass. Snap, the sixspeeder’s beautifully tactile short-throw lever is flicked back to second and the throttle squeezed to the floor. This is it, our first real chance to extend the MX-5’S heavily revised 2.0-litre Skyactiv-g engine and see to what extent it really changes the character of our 2016 Car of the Year winner.
Instantly obvious are an extra level of zingy eagerness to rev, and a mid-range that feels especially sweet. The benefits of moving to a dual-mass flywheel seems most evident in the crispness of the throttle response, with any sense of slight low-rev doughiness now replaced by a satisfying immediacy of response of tacho to pedal. The slight bump to the torque curve also surely contributes to this – it’s up 5Nm to 205Nm, developed 600rpm lower at 4000rpm.
Anyway, the extra 17kw Mazda has extracted from the extensive raft of revisions reside at the top end, obviously, so you need to keep your foot planted. The old point of peak power – 6000rpm – is now spun past with a dismissive sweep of the needle, the exhaust note hardening to an insistent yet cultured rasp. Just shy of 7000rpm was where the old engine would stutter up against the limiter; that figure is 500rpm short of the new redline. So even though power flattens off past the peak at 7000rpm, it doesn’t drop off a cliff, and drivers who enjoy wringing out everything their car
can offer will appreciate the extra headroom provided by a limiter that now doesn’t call time until 7700rpm. On the roads of our test route, we often held second or third gear at the top of the rev range, rather than force a wasteful upshift only metres before the braking point for the next bend.
If you’re a fan of all the fascinating oily bits of internal combustion, the changes to the 2.0-litre make interesting reading, not because they’re radical, more because they’re extensive. The goal, Mazda’s engineers are happy to admit, was to give the 2.0-litre engine a character more like that of the sweet, rev-happy 1.5. Fact is, the merits of the 1.5 versus the 2.0 were debated at COTY 2016 with the sort of fervour that would be normally reserved for Australia’s annual change of Prime Minister, or vanilla snot-blocks versus custard tarts. The 1.5 is the purist’s engine (an irrefutable fact, because that’s what our summation in Showroom says), its output deficits accepted as the price you must pay for its more free-spinning character and sweeter tonal goodness.
The new 2.0-litre succeeds in making that a mostly moot point. To achieve this, first came a weight reduction to the rotating assembly, with new, shorterskirt pistons each trimming 27g; slimmer rods and new bolts cut a further 41g each. The crank, meanwhile, had to cop a slight weight increase due to the eight revised counterweights needed to keep it vibe-free at the higher rev limit.
Breathing improvements go further. On the intake side are a better flowing manifold (that also cuts charge temperature), larger valves, reshaped ports, and new injectors that spray fuel more accurately. Upgrades to the ECU allow a more tailored three-stage injection strategy that varies according to engine speed.
On the exhaust side, both lift and duration of the revised cam have been increased, opening larger exhaust valves that flow into reshaped ports. To capitalise on the improved exhaust flow, there’s now a new manifold with larger internal diameters. So nothing radical here, yet there’s something satisfyingly old-school about it all, in a turbo era where more power and torque almost invariably come via a software change to the ECU.
As for the other improvements, they advance the MX-5’S safety credentials, and address the sort of issues that clearly irritate owners. Of the latter, the addition of telescopic column adjustment is the most significant. Okay, it only moves by 30mm, but in a cabin as snug-fitting as that of the MX-5, it’s like having your highriding trouser cuffs let out by that amount. For my six-foot frame, it allows the wheel to come in for a more bent-elbow, straight-legs position. Pity the handbrake lever still makes contact with my left
knee, but it’s still preferable to an electronic button.
As for safety, the updates amount to improved AEB to better recognise pedestrians and cyclists, a reversing camera mounted discreetly in the revised rear bumper, and traffic sign recognition.
Prices are up $750 across the board, but what hasn’t changed is the MX-5’S chassis tune or handling balance. The higheroutput engine makes it easier to extract the MX-5’S best, but doing so still requires that the conditions are in your favour. Slow traffic in hilly terrain can spoil your flow, and an extra 17kw/5nm can’t overcome that. Nor does it magically bring an ultra-planted front end that begs you to wail on it. No, the MX-5 remains very much a fingertips car that telegraphs its limits early, and, via its rolly set-up, brings the rear into play almost before you’ve fastened the seatbelt.
So not for everyone, but for the fan base, any agonising over the 2.0-litre’s power versus the 1.5’s sweetness has been comprehensively resolved.
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