Irvine, California - Mazda’s long-running MX-5 has been updated for 2019 with a raft of detail improvements, several new features, and a 17 percent increase in power. And that’s been done the old-fashioned way, with attention to detail inside the two-litre Skyactiv-G petrol four, rather than by remapping the ECU for more power.
The Mazda whitecoats started by paring away the skirt area of the pistons, saving 27 grams on each one, and cleaning up the con-rods to save a further 41 grams each. That doesn’t sound like a lot, but when they’re going up and down 7000 times a minute, the reduction in inertia is significant.
Then they reshaped the inlet ports and fitted new high-diffusion, higher-pressure fuel injectors to improve fuel swirl in the combustion chamber, increased the opening angle and lift on the exhaust valves - a classic ‘stage one’ modification - widened the inside diameter of the exhaust manifold, and added a new exhaust system for a richer, more sonorous engine sound, and a 30 percent reduction in pumping losses.
The conventional flywheel was replaced by a lighter, dual-mass flywheel, and the final drive ratio shortened from 3.454:1 to 3.583:1, sacrificing a little top-end speed for a notable improvement in acceleration.
The result is an engine that revs harder - the redline goes up from 6800 to 7500rpm - and delivers a claimed 133kW at 7000 revs and 205Nm at 4000rpm, with more torque across the rev range, compared to the 118kW at 6000 revs and 200Nm at 4600rpm of its predecessor.