McLaren Artura hybrid revealed

It’s out with the V8 and in with the V6 as the McLaren Artura sends the British supercar maker into a brave new world of electric-for-speed hybrid power.

With 500kW of power and 720Nm of torque, the twin-motor Artura retains everything that makes McLarens McLarens, including twin turbos and a carbon-fibre tub, but adds so much more – without adding much weight.

It’s the first McLaren to ride on the company’s new MCLA (McLaren Compact Lightweight Architecture), the first series-production McLaren hybrid and the first McLaren to offer over-the-air (OTA) software updates.

The Artura is also the first McLaren to offer 30km of pure EV driving, which is important at least in Europe these days, and it’s also a plug-in hybrid – though it takes a full 2.5 hours to charge what is, actually, a very small battery.

It’s not the first McLaren to run out to 320km/h, though, so it retains all the speed the brand is famous for and it now also adds a five-year warranty, for anybody frightened off by the plug-in hybrid system.

The McLaren Artura hits 100km/h in three seconds flat, 200km/h in 8.3sec and 300km/h in 21.5sec.

McLaren has managed it all while keeping the Artura’s weight down to 1395kg dry, or 1498kg according to the full-fluid DIN measuring system.

The big questions around the Artura weren’t even so much around whether or not to give it hybrid power, but whether or not to continue with the so-called Sports Series that had been McLaren’s entry point.

Turns out every buyer of one of McLaren’s cheaper models thought they were buying a supercar anyway and, given they still had the same V8 and carbon tub, it’s easy to see why.

Now, the line-up is more settled, with the GT at one end, the hypercars at the other and the Artura positioned between the GT and the 720S.

It adopts so much new technology (which will find its way into other McLarens in due course) that it’s hard to know where to start. It’s easier to declare what it retains.

The Artura keeps rear-wheel drive, even if it now uses an electronically controlled e-differential for the first time.

It also retains hydraulic steering, rather than adopting an electric power steering (EPS) set-up, because McLaren insists it’s the only way to deliver the steering poise its drivers want.

But it seems like it was a technology they ran out of resources to give the Artura, because Ferrari and Porsche manage EPS just fine.

It keeps a two-seat layout and a tiny luggage area (160 litres, up in the nose where there’s no front diff), but the body construction (at least for the roof and rear deck) switches to aluminium.

It keeps a philosophy of light weight, with more than 500 single carbon-fibre pieces put together into 72 pre-forms to make 11 sub-assemblies to eventually turn in to one carbon-fibre tub.

It’s a much more comprehensive thing now, reaching farther back into the engine bay, housing the 7.2kWh hybrid battery beneath and behind the passenger compartment. The tub extends up into the B-pillars, so that the seat belts even mount into it.

Among what’s gone is reverse gear, whose role has been taken up by the electric motor, in one big hint at the powertrain’s advancement.

McLaren has long made its living with twin-turbo V8s, including the latest M840 in the 720S, but the Artura has switched to a 2993cc V6 dubbed the M630.

It’s no off-the-shelf item, either, but a purpose-engineered 120-degree motor with hot-vee turbocharging and some fancy ventilation to get rid of all that 900-degree air.

Now, it’s the first production car to ever use 120 degrees as a V6 bank angle and the only other V6s were used in Formula 1, by Ferrari, twice (once with a turbo and once without).

McLaren’s rationale for slicing off two cylinders of tradition is entirely logical: there’s a 15.4kg e-motor attached to the back of the V6 and it tips in all the torque (pretty much) that it loses. And it also saves on fuel.

And there are the sums. The V8 McLaren motor in the 720S is 50kg heavier than the Artura’s V6, but the hybrid system adds 100kg, more or less.

Its rationale for the radical 120-degree layout is every bit as logical. It means the V6 can be dropped even lower in the chassis, a full 40mm lower than the V8 in the 720S, and that can only help the handling.

The downside is that it needs a balance shaft, which adds weight and complexity, though the two banks share a crankshaft journal to shrink the length of the crank.

The engine is actually narrower than the V8, too, even though the traditional McLaren motor has a 90-degree vee angle.

The main reason for that is McLaren’s choice of a hot-vee set-up for the pair of turbochargers, reducing the length of the V6’s manifolds and, therefore, turbo lag.

Hot-vee engines are nothing new, with Ferrari debuting its first variant on the 126 Formula 1 car back in 1981 (coincidentally, also with a 120-degree vee layout, and also with six-cylinder power).

BMW’s M division pioneered hot-vee production engines with the N63 V8 in the M5, followed in quick succession by Mercedes-AMG, Audi, Porsche, Bentley and even Lamborghini.

Hot-vee motors reverse the cylinder heads of conventional turbo set-ups, because they slurp up incoming air from outside the vee and blast it out through the turbos inside the vee for, theoretically at least, reduced turbo lag.

“We've got this really direct pathway from the turbo straight out the back of the car. You almost feel like you can look down the exhaust pipe and see the turbine,” McLaren’s chief engineer Geoff Grose says.

The downside to this in a mid-engined car is heat build-up, but McLaren has engineered in two ‘chimneys’ to take all that hot air out, which makes for a very pretty heat map, pulling the engine bay temperature down from 900 degrees to 240.

There are other engineering tricks, too, like shifting the valve gear to the rear of the engine, so it dangles over the transmission rather than being squeezed against the cabin bulkhead.

It has taken advantage of 3D printing in the casting to cast the bores directly into the block, allowing the bore spacings to shrink from 14mm to just seven, saving 27mm in overall length alone.

It’s an unusually long-stroke motor for a sports car, with an 84mm bore and a 90mm stroke making it massively understroked for an engine that revs to 8500rpm. That delivers a mean piston speed of 25.5 metres/second, which is getting up there.

McLaren went an unusual way here, plumping for an axial-flux disc motor and, instead of doing it the easy way and putting it on the front axle to make an all-wheel drive, it is sandwiched between the V6 and the eight-speed transmission.

Yes, it can manage a claimed 30km of EV driving and, yes, it’s a plug-in hybrid, but that’s not specifically the reason the electric motor is in the Artura.

Instead, its primary purpose is “infill”, adding torque and punch where the V6 motor doesn’t have it.

“Our target is to deliver consistent performance over a whole track session rather than a hot lap,” McLaren’s head of powertrain Dr Richard Jackson said.

“We developed it for a 10-lap session at Nardo’s handling track, and that’s a very demanding track.”

The 15.4kg motor has 70kW of power and 225Nm of torque and, unusually, it can keep working at up to the maximum speed of the V6 motor.

“The torque in-fill capacity kicks in if the torque ever dips below 2500rpm,” McLaren’s head of electric drive technology Sandaj George said.

“We used axial flux technology because radial flux would be heavier. It delivers more energy from the nickel cobalt manganese battery.”

That battery is integrated into the carbon tub’s rear-end, right down low for weight distribution, and it’s cooled by refrigerant from the air-conditioning.

“The e-motor is very good for leaving the house in the morning or returning in the evening or use in urban environments,” George said.

“Comfort mode is more hybrid when it drives. Above 60km/h it will run ICE and switch off the combustion below 40.”

It also eschews most modern thinking by avoiding using the brake pedal to regenerate energy into the battery.

“The charge limits are limited by the current source, so we use engine braking instead,” Grose said. “We don’t want different behavior under braking.

“In the track mode we can provide energy from the ICE when we are not using maximum torque for performance.”

The hybrid system weighs a total of 130kg, but McLaren argues it can’t be considered as an apples for apples weight comparison with the 600LT, largely because of the weight savings with the move to the V6.

“There is 30km of EV range and that costs you something in weight,” George said.

“We have almost completely offset the weight of the hybrid, but not quite. It could be in the region of 20-30kg heavier than a non-hybrid.”

The McLaren Artura will be the British brand’s first model to accept OTA updates, and McLaren has a mostly open mind about what is future-proofed and what isn’t.

“OTA covers 70 per cent of the key modules,” Grose claimed. “OTA is baked in at this stage, so we can change and update past the point of sale to the customer.

“We are staying away from ECU systems, but as long as the hardware is in the car to match it we are open to it.”

That’s not where the cool stuff ends, though, because the Artura runs Pirelli’s Cyber tyre technology, which inserts sensors directly into the wheel and transmits data to the cabin via Bluetooth.

Another step forward is the Artura’s ‘broken wishbone’ rear suspension, which is claimed to stiffen its rear wheels against toe-angle changes by 75 per cent.

“You normally have toe out under acceleration and toe in on braking.” Grose said. “We are always looking to minimize any changes to the toe angle, and this works.

“We are making this massive increase in kinetic stiffness and we have moved the point of the lower wishbone outwards.

“It’s not just the rear-end, though. We use double wishbones at the front, and the variable wall thickness anti-roll bar saves 1.4kg.”

The Clubsport seats have made a big step forward in technology, with McLaren insisting the manually controlled pair saves 30kg over the lightest electronically adjusted versions.

McLaren is also pleased with the way it has avoided electronic boosting for the engine sound in the cabin. Instead, they have a pipe from the exhaust into the cabin to deliver only authentic exhaust noise.

The hybrid supercar has three drive modes – Comfort, Sport and Track – which each of these adjusting the stiffness of the dampers, as well as altering the settings for the E-diff.

The driver gets an all-new, configurable 10-inch HD instrument cluster, while the passenger can fiddle with the 8.0-inch MMI, which includes the track telemetry, the surround-view cameras and a range of apps.

There is USB-B and USB-C charging, a new ventilation system that runs off the hybrid battery’s high-voltage power and an all-new audio system, too.

Its collection of driver-assistance systems includes lane-keeping, adaptive cruise control and road-sign recognition systems.