Sweeter engine dominates Mazda MX-5 Upgrade.
WHAT IS IT?
An update of Mazda’s 4th-generation, COTY-winning sports car, focusing on improving the 2.0-litre engine, adding safety and convenience features, and tweaking a few weak spots.
WHY WE’RE DRIVING IT
It’s our 2016 COTY winner, and some excellent roads in the Gold Coast hinterland beckoned. Be rude to say no.
THE WHEELS REVIEW
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 six-speeder’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 the extent to which it really changes the character of our 2016 COTY 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, that often allowed us to hold 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 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, shorter-skirt 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 in 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 high-riding 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 higher-output 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.
THE WHEELS VERDICT
Full credit to Mazda for putting its focus on the areas of the MX-5 that needed attention, and leaving the rest alone. The heavily revised 2.0-litre is noticeably improved in its throttle response, increased rev ceiling and peak power. Sounds better, too, with no downside to consumption. (The base 1.5-litre engine is also improved – see below – but the gains are tiny, and we didn’t get to drive it). Then there’s the upgrades to the safety suite, the addition of a telescopic steering column, rear-view camera, and other details that count. All of which makes the modest price rise of $750 across all models entirely palatable.
PLUS: Extra zing and revs from revised engine; steering column now has telescopic adjustment; rear-view camera added; upgraded safety; still wonderfully tactile and involving
MINUS: No digital speedo; RF’s folding-panel roof can’t be opened above 10km/h; no passenger grab handle.
But what about the baby?
The 1.5-litre engine also gets revisions – essentially, piston shape and combustion chambers – but the gains are tiny: power up by a single kilowatt, (now 97kW); torque up by 2Nm (152Nm). Driving in cool morning air versus a hot afternoon would make a greater difference. Take up of the 1.5 in Australia is minimal; just 5 percent, hence it’s only offered in base Roadster form. As for the automatic (add $2K), it wasn’t available to drive at the launch, but Mazda advises the final-drive ratio of the 2.0-litre slusher is shorter (from 3.24:1 to 3.58) for more lively acceleration.
Model: 2019 Mazda MX-5 RF GT
Engine: 1998cc 4cyl, dohc, 16v
Max power: 135kW @ 7000rpm
Max torque: 205Nm @ 4000rpm
Transmission: 6-speed manual
0-100km/h: 7.1sec (estimated)
On sale: Now
By Ash Westerman, 14 Sep 2018 Reviews