Powertrains, suspension, steering, brakes and safety equipment befitting a grand tourer

Everything about Stinger has been engineered to ensure it is an authentic modern gran turismo. From its torquey turbocharged engines to its eight-speed automatic transmission, fully independent suspension – with switchable modes in the ’GT S’ – powerful brakes and variable steering, it is a car built for covering long distances swiftly, comfortably and safely while delivering maximum driving pleasure.

The body is composed of 55 per cent high-strength steels to keep weight to a minimum so that Stinger is as lithe and agile as it looks while ensuring robustness in the event of an accident, and there is a battery of advanced driver assistance systems to make that accident less likely. And extensive work on sound-deadening ensures it is as refined as it is comfortable, but occupants can still enjoy the refined sporting tones of the Stinger's turbocharged engines thanks to an Active Sound system –­ the first in a Kia.

Three turbocharged engines

Grand tourers should not only be beautiful, comfortable and luxurious – they must also be fast. The three turbocharged engines chosen for Stinger are ideally suited to its role as a long-distance gran turismo.

On the one hand the 3.3-litre twin-turbo V6 T-GDi is the fastest-accelerating Kia ever, with a 0-60mph time of 4.7 seconds and a top speed of 168mph, while on the other the 2.2-litre CRDi's combined fuel consumption of 50.4mpg gives it a touring range of comfortably more than 600 miles. In between there is the 2.0-litre T-GDi offering much of the best of both: acceleration from 0-60mph in 5.8 seconds with combined fuel economy of 35.8mpg, allowing it to cover more than 450 miles before the driver will need to stop for fuel.

The 2.0-litre, 1,998cc T-GDi (Turbocharged Gasoline Direct injection) engine is from the Theta II family. It is an all-aluminium unit with identical cylinder bore and piston stroke measurements of 86mm. In Stinger it develops 244bhp at 6,200rpm and 353Nm of torque all the way from 1,400 to 3,500rpm, ensuring outstanding driveability. The engine features a scroll turbocharger and continuously variable valve timing on both the inlet and exhaust sides.

Its low displacement conforms to Kia's policy of downsizing to maximise efficiency. Smaller engines cause less friction, while direct injection cools the charge down, allowing the engine to run leaner without causing detonation. The intake manifold is lightweight composite while the wastegate is electronically controlled for precise boost control at part throttle. The block is reinforced to deal with the load being placed upon it, and there are large coolant ports in the head for optimum heat dissipation.

The 2.0-litre T-GDi engine allows the Stinger to accelerate from 0 to 60mph in 5.8 seconds and on to a top speed of 149mph. Yet it is capable of 35.8mpg while cruising, while CO2 emissions are 181g/km.

The 3.3-litre, 3,342cc twin-turbo V6 T-GDi is a member of the Lambda II range and produces 365bhp at 6,000rpm and a huge 510Nm of torque starting at 1,300rpm and continuing uninterrupted until 4,500rpm.

It features an aluminium block and heads and was developed during a rigorous testing regime focused on responsiveness and efficiency with durability and reliability. There are twin single-scroll turbochargers, an air-cooled intercooler and an integral turbo and exhaust manifold to reduce weight. An electronic wastegate and thermostat help to improve responsiveness. Continuously-variable valve timing (CVVT) enhances intake operation range and operation speed while reducing pumping loss. There are sodium-filled exhaust valves to boost performance and efficiency while offering structural reinforcement for improved durability.

The twin-turbo V6 makes Stinger the fastest-accelerating Kia ever. From standstill to 60mph takes just 4.7 seconds, and the top speed is 168mph where permitted. Yet the extensive testing regime to ensure durability and responsiveness has also helped efficiency: combined fuel consumption is 28.5mpg, while CO2 emissions are 225g/km.

The 2.2-litre CRDi is from the R family, developed and made in Korea, and delivers 197bhp at 3,800rpm and 440Nm of torque across a wide range – 1,750 to 2,750rpm. It is a 2,199cc 16-valve four-cylinder unit with chain-driven overhead camshafts and a variable geometry turbocharger and intercooler. The fourth-generation common-rail fuel injection system features piezo injectors, and the injection pressure is up to 2,000 bar. Other technical highlights include an actuator which gives precise turbocharger control for superior acceleration and fuel economy and a special coating to reduce friction on the piston skirt.

The intake manifold, cylinder head cover and oil filter housing are made of plastic to help trim weight. With an intake manifold featuring electronic swirl control and an exhaust gas filtration system that promotes the recirculation of clean, cool, low-pressure exhaust gas, the R-family diesel engine is clean and efficient.

With combined fuel consumption of 50.4mpg, the Stinger 2.2-litre CRDi is capable of travelling comfortably more than 600 miles on a single 60-litre fill-up, while its CO2 emissions are just 154g/km. But it is anything other than a poor relation to the petrol models for performance. Its strong and easily accessed torque allows it to accelerate from 0 to 60mph in 7.3 seconds, and the top speed is 143mph.

To ensure occupants can enjoy the refined sporting tones of the Stinger's turbocharged engines, the car is the first Kia to be fitted with an Active Sound system. This relays the engine note to the cabin through the car's audio system rather than the more conventional actuator. It was engineered in Europe and can be customised through the Drive Mode Selector according to which of the five programmable settings the driver has chosen.

Eight-speed automatic gearbox

All versions of Stinger drive the rear wheels through an electronic eight-speed automatic gearbox. It was designed in-house and rewards drivers with immediate shifts and optimum fuel efficiency. Stinger’s transmission marks Kia’s first use of a Centrifugal Pendulum Absorber (CPA) torque converter more typically found in aviation and racing applications. CPA reduces torsional vibrations through the drivetrain.

The transmission offers up to five different shift and throttle programmes, accessed through the car’s electronic Drive Mode Selector. Drivers can leave the car to shift for itself, or change gears with steering wheel-mounted paddles. A Limited Slip Differential is fitted to all models so that torque is transferred to the rear wheel with most grip.

ISG, Kia's engine stop/start system to ensure no fuel is wasted and no emissions are released when the car is stationary, is standard. The engine cuts out as soon as the driver brakes to a standstill and restarts when the brake pedal is released.

Running gear

A gran turismo must provide exceptional comfort for occupants on the long distances it is designed to cover, but it must also reward enthusiastic drivers with pliant but controlled suspension, alert steering which does not make the car nervous and powerful brakes. Thanks to the extensive testing regime on all kinds of roads, in all weathers and across several continents, Stinger meets those demands. Right-hand-drive cars have undergone additional testing in the UK to meet the unique challenges of the country's roads.

All versions have fully independent suspension through MacPherson struts at the front and a five-link set-up featuring double wishbones at the rear, but there are two different systems. ‘GT-Line’ and ‘GT-Line S’ have a passive set-up, while ’GT S’ introduces adaptive Dynamic Stability Damping Control (DSDC), which can be changed through the Drive Mode Selector. DSDC allows the driver to choose a more comfort-oriented Normal setting or a Sport setting which introduces more powerful damping force. DSDC varies the stroke length of the shock absorbers according to information on acceleration, braking and steering obtained from sensors.

A variable-ratio version of Kia's rack-mounted Motor Driven Power Steering (R-MDPS) is standard on the ‘GT S’, and this can also be adjusted via the Drive Mode Selector. The Normal setting requires less turning effort from on-centre, becoming progressively firmer as more lock is added. Sport requires more initial effort, while shorter gearing ensures more immediate response by reducing the need for larger steering inputs. Steering response also benefits from mounting the electric motor on the rack rather than the column. The steering therefore provides the same duality as the suspension.

Stinger's brakes have had more development work than those on any previous Kia to ensure they are up to the performance of the engines. There are ventilated discs of varying size at all four corners for the 2.0-litre T-GDi and 3.3-litre T-GDi V6 models, with ventilated front discs and solid rear discs for the 2.2-litre CRDi models.

The brakes for the 3.3-litre GT S were co-developed with Brembo and are 350mm front and 340mm rear, holed and grooved, to provide high heat capacity with low fade, even in repeated heavy use. They were developed on some of the highest mountain passes in Austria, Germany and Spain as well as around the Nürburgring. There are quad-piston front calipers and dual-piston rear calipers.

There are 18-inch alloy wheels with 225/45 R18 tyres for GT-Line and GT-Line S, while the GT S has 19-inch alloys with 225/40 R19 tyres at the front and even wider 255/35 R19 tyres at the rear.

Safety

Stinger may evoke memories of the golden age of gran turismos, but it is not a retro car. Its advanced driver aids take into account that roads are busier and there are more distractions than yesteryear.

Stinger's safety provisions begin with its sturdy body, 55 per cent of which is composed of high-strength steels so that rigidity and crash protection do not come at the expense of excessive weight. Structural adhesives are used extensively and the attachment points for the powertrain and chassis, where loads are most concentrated in the vehicle’s frame, are extremely rigid. By strengthening the longitudinal and transverse structures and using an engine room strut bar, the frame exceeds competitive car standards.

In terms of crashworthiness, the Stinger exceeds all competitors. The side member is formed from 80 K-class steel. The rear lower member is formed from 150 K-class steel, and as much available crash space as possible has been included. To protect passengers in a rear collision, the lightweight high-stiffness body in white (BIW) is so strong that it surpasses European car standards.

To achieve this, the lower part of the body, a critical area in a collision, is made of hot stamped, ultra-high-strength steel with a large steel plate. Carefully defined load paths channel impact forces away from the passenger cell, and there are seven airbags – including one for the driver's knees – to protect occupants.

However, Stinger has been engineered to ensure that, as much as possible, such features will not be needed through a comprehensive network of advanced driver assistance systems. All versions have Autonomous Emergency Braking, which automatically intervenes to stop the car if the driver fails to respond to a potential accident, and there is Lane Keep Assist to prevent a driver straying into an adjoining lane accidentally, and High Beam Assist to adjust the headlights according to other traffic and local lighting. Driver Attention Warning alerts a tired driver that it is time to take a break, and there is a Speed Limit Information system.

GT-Line S and GT S supplement this with Blind Spot Detection with Rear Cross Traffic Alert: together, these act as an extra pair of eyes for the driver, warning of vehicles approaching out of his or her eye-line when changing lanes or exiting parallel parking spaces. An Active Bonnet is standard with all three trim grades to reduce damage to pedestrians' heads in a collision.

Stinger has Electronic Stability Control linked to Vehicle Stability Management (VSM) to correct potential skids without any intervention from the driver. VSM incorporates a new dynamic torque vectoring system which monitors driver inputs and road conditions and automatically applies power and braking force to the inner rear wheel to minimise understeer and enhance tractability and steering feel.