Mazda CX-60 3.3 e-SkyActiv D 2023 first drive
Short on premium-market refinement, but the efficient diesel straight six might be worth overlooking its faults for
While Europe’s recently announced Euro 7 emissions regulations may have forced some fresh investment here and there, few car makers seem to be doing proper research and development on brand-new combustion engines anymore. Most have other priorities - and whether they’re quite the right ones still remains a matter of debate.
Mazda - as ever - is a little different. It believes in a global decarbonisation strategy that makes room for piston engines while there’s still call for them, and while they can still be made more efficient. And, as the new Mazda CX-60 e-SkyActiv D clearly demonstrates, in the case of the bigger ones in particular they absolutely can.
The firm’s product renewal schedule happens to have just delivered a new family of larger, longways-engined SUVs: the CX-60 last year, the larger seven-seat Mazda CX-80 to Europe later this year, and their related -70- and -90-suffixed siblings to markets elsewhere in the world. And, because the markets in which those cars will sell still have an appetite for combustion engines (Japan itself remains fairly EV-sceptical), they need new big engines to match - both petrol and diesel - in addition to hybrid and plug-in hybrid options.
That’s how it is that the Mazda CX-60, which launched in the UK last year in four-cylinder PHEV form, is now getting a box-fresh, 3.3-litre straight-six turbodiesel engine - whose appearance, to European eyes at least, may seem something of an anachronism. Why put an only mildly hybridised six-cylinder diesel into a mid-sized, premium-priced SUV, then, at a time when so many customers apparently wouldn’t contemplate spending premium-level cash on a car that didn’t come with a plug? The answer, as Mazda has it, is pretty simple: in a car of this size, a six-cylinder diesel is actually cleaner and more economical than a four-pot.
As Heiko Strietzel, manager of the powertrain development team behind the unit, explains, a bigger engine can produce the torque necessary to cover most of the propulsive needs of the CX-60 at lower loads, revs and combustion temperatures than an equivalent four-pot. By applying an innovative new piston design, and a fuel injection technology called DCPCI (Distribution-Controlled Partially Premixed Compression Ignition), that six-cylinder engine can more than offset the impacts of its greater mass, friction and swept capacity simply by remaining in a closely-controlled, lean-burn state of operation for longer than a four-pot might.
“Because it can operate at better than 40% thermal efficiency for so much of the time, our research confirms that the 3.3-litre, six-cylinder diesel engine is right-sized for the CX-60,” Strietzel says. The car’s WLTP fuel economy and carbon emissions lab test results would tend to agree when compared to those of the car’s four-cylinder diesel, mid-sized SUV rivals. Neat trick, eh? For their next one, let’s hope for an atmo 7.3-litre petrol V12 that’ll do 150mpg.
The diesel will be available in two states of tune: this rear-driven 197bhp version, and a 251bhp version that comes exclusively with four-wheel drive. Both use a new eight-speed automatic transmission designed and developed in-house by Mazda, which has a pair of wet clutches instead of a torque converter, and a 48-volt mild hybrid system which can contribute up to 113lb ft into the driveline, but which tends only to boost the engine’s performance rather than driving the wheels all on its own.
There’s a distantly coarse chug about the engine’s audible character at idle; it puts you in mind just a little of the Pride of Cherbourg leaving its harbourside berth. But at cruising revs, the CX-60 settles into smoother stride. Mazda accepts that its lean-fuelling calibration (which the motor adopts at crank speeds up to about 2200rpm, and at up to about 250lb ft of load) does make the combustion sound a little more clattery than modern diesels typically are. It opted for that ‘perfect balance’ straight-six cylinder configuration, at least in part, to mitigate the fallout.
The desired effect is mostly achieved. The engine revs quite freely up beyond 4000rpm, with generous and wide-spread torque, is quiet enough under light loads, and - while there’s a bit too much digital engine noise synthesis in car, which you can’t fail to notice at full power - it’s still fairly rich and enticing to extend, and potent-feeling under your foot. The gearbox shifts smoothly and with intelligent timing, seemingly knowing when to hold a higher gear and when to drop it. It has a paddleshift manual mode, whose shifts could be a little bit quicker - but they're certainly fast enough not to offend.
It’s a shame that so much else about the Mazda CX-60 isn’t quite up to a commensurate level of richness or sophistication. The car’s cabin has a good driving position, offers adult-appropriate passenger space, and is appointed in a mix of quite appealing textiles and leathers - but also of cheaper-looking switches and mouldings in plenty of places. The haptic feel of key touchpoints - from exterior door handles to gear selector - is surprisingly plasticky and lightweight; and its doors close with a tinny clang. Cabin isolation on the move, from both wind and road noise, is a little disappointing likewise. And while the car handles and steers well for something of its type, it can ride in slightly sproingy, jittery, occasionally noisy fashion.
In so many ways, Mazda still clearly has a bit to learn about making really convincing, premium-level passenger cars. But in one respect in particular - a 3.3-litre six-pot diesel engine that feels ideal for towing and long-distance driving, and which can return 50mpg easily and 65- if you try a bit - it’s now got a selling point that plenty of us, especially those of us who don't pay benefit-in-kind tax, and who aren't in a position to regularly charge an electrified alternative, could surely find a use for.
