It has been many years since JLR engineered an inline petrol ‘six’ to power its top models but, says Iain Robertson, it is a most thorough job that clarions strong performance, allied to perfect balance and a deliciously purring exhaust note.
People ‘of a certain age’ and today’s classic car fans will recall the virtues of the straight-six engine, as was fitted to the Triumph 2000 and 2.5PI, the ‘poor man’s Rolls-Royce’ Rover 3.0-litre and several first-rate BMW and Mercedes-Benz models over the years. While a V8 motor could be said to offer exceptional levels of refinement, only a V12 can truly exceed the potential of an inline-six.
Of course, during the late-1960s, when BLMC, at one time our biggest carmaker in the UK, fell for the guile of the former small-block Buick V8 engine, installing it initially in the Rover 3.5-litre saloon and coupe (always known as the ‘Prime Minister’s Rover’) but then in detuned form in the first-ever Range Rover of 1970, it was the burbling whiff of Americana that engaged with the British car-buying public. The Triumph division of the company even developed its own, expensive and desperately unreliable 3.0-litre V8 engine for the sporty Stag model.
However, both Jaguar and Land Rover had persevered with straight-six powerplants. Even today, the sound of the former, mainstay, twin-cam Jag engine (in 2.4, 2.8, 3.4, 3.8 and 4.2-litre guises) is a soul-stirring experience. The inherent balance of six pistons in a long but skinny installation led to the creation of the inimitable ‘power-bulge’ in the gorgeous E-Type’s bonnet. However, Land Rovers own, if ancient and slow, 2.6-litre six-cylinder engines soldiered-on most dependably in the Defender model.
Available initially on a special edition HST version of the Range Rover Sport model, the all-new 3.0-litre, 396bhp, 405lbs ft Ingenium engine is not just more responsive and better balanced than the previous V6 petrol unit (and even the company’s predilection for V8s, as suggested above) but it despatches the 0-60mph blast in 5.9 seconds, before maxing-out at 140mph, figures that pale the earliest but strangulated 3.5-litre V8 in the Rangie. The new unit is electrically supercharged, rather than turbocharged, which ensures that throttle responses are instant.
Supported by a twin-scroll blower and Continuous Variable Valve Lift technology, which together boost power and help the engine to breathe more efficiently, the design of the all-new six-cylinder Ingenium family engine optimises performance and fuel economy (up to 30.5mpg) as well as reducing emissions (213g/km) with tremendous poise and refinement. Its concession to ‘electrification’, which the company had promised but has taken a long time to achieve it, is the use of Mild Hybrid technology.
Not yet of a plug-in type, it is an intelligent system that is based around an all-new Start:Stop device that switches off the engine, when stationary, and pairs the latest unit with an electric motor. It allows the system to harvest energy through regenerative braking and store it in a 48V battery for subsequent use, such as when pulling away from a standing start. In that respect, it is broadly similar to the mild hybrid technology applied to the SHVS 1.2-litre engine used by certain Suzuki models. Its integrated starter/alternator enables silent stop-starting. Developed in-house by JLR, the latest six-cylinder Ingenium engine is being manufactured at the £1bn Engine Manufacturing Centre, in Wolverhampton, West Midlands, alongside the current four-cylinder petrol and diesel units.
In-line six-cylinder engines are inherently better balanced than V6 alternatives, which were chosen by various manufacturers for their compact dimensions. Inevitably, JLR’s new Ingenium unit builds on a stated promise to optimise efficiency in all operating conditions and will soon find a home beneath the bonnets of other Land Rover and Jaguar motorcars. Perhaps, had the company introduced this engine earlier, it might have stemmed the sales downturn in its Chinese market sector, which has created most of the company’s present financial woes. It can only be hoped that it is a recoverable position.
While ramping-up production of the new inline-6 petrol engine, JLR has decided to introduce it on the special edition Range Rover Sport HST model, which features an unique combination of interior and exterior upgrades that include bespoke badging and carbon fibre trim on the bonnet, front grille, side vents and tailgate. Buyers will also have a choice of two alloy wheel designs and five exterior colours – Santorini Black, Fuji White, Indus Silver, Firenze Red and Carpathian Grey. The HST is identifiable by its red brake callipers that provide superb stopping power. Riding on air suspension with electronically-adjustable dampers, the car’s handling is surprisingly crisp and precise.
Mated to an 8-speed automatic transmission, which also features an electronically-controlled low-ratio transfer ’box, on-road progress is silken, while the Sport HST’s off-road prowess is renowned. The ride comfort in its softest (default) mode is supremely cosseting and even instils elements of body roll control, thanks to the semi-adaptive suspension components. The overall stability of the car is helped by the relative lack of either pitch, or dive, under acceleration and braking forces respectively. Select Sport mode and the car is only slightly less comfortable.
Inside, the 16-way dynamic front seats feature an updated colour pattern, with suede-cloth detailing on the steering wheel and gear lever, satin chrome shift paddles and an HST badged facia. The digital instrumentation and plethora of switchgear can take some time to acclimatise to but it is not as random as other models in JLR’s line-up. There is a good enough range of adjustability in the driver’s seat and steering column (both electrically operated), to provide a commanding and comfortable seating position for a wide array of driver dimensions. In addition, the available suite of safety enhancements includes Adaptive Cruise Control, Stop:Go and Steering Assist, alongside high-speed emergency braking. Owners also benefit from traditional Land-Rover off-road features, such as Terrain Response Two.
While list prices start at a hefty £81,250, prior to dealer discounts being negotiated, demand is sure to be strong for the reintroduced inline-6 petrol engine, which will satisfy traditionalists, while encouraging newcomers to the brand. However, if JLR is to rise above and learn from its recent malaise, it is going to have to look more carefully at its model pricing strategy.