Efficient engines at the core
While the new Peugeot 508 sets high standards in design, quality, efficiency, comfort and safety, it also benefits from the French marque’s technological expertise and innovation in terms of the drivetrains its employs.
For the South African market, the 508 is offered with a choice of three engines – a turbocharged petrol and two turbodiesel units – together with either manual or automatic transmissions. Drive is to the front wheels in all instances.
HIGH-PRESSURE TURBO PETROL
The sole petrol engine on offer in the 508 is the proven EP6CDT turbocharged four-cylinder unit. Fitted with electronic fuel injection, advanced engine management and a high-pressure turbocharger, this power unit always feels more muscular and willing than its 1 598 cc capacity suggests.
This is borne out by the output figures. The 1,6-litre engine is credited with maximum power of 115 kW at 6 000 r/min, while the torque output peaks at 240 Nm, already on tap from 1 400 r/min and sustained to 4 000 r/min.
The 1.6 THP engine powers the 508 1.6 THP Active, driving the front wheels via a six-speed manual gearbox. It’s also the motive heart of the 508 Allure 1.6 THP, but coupled to a six-speed automatic gearbox.
HDI TECHNOLOGY: TRACTABLE PERFORMANCE
The two turbodiesel engines on offer both employ Peugeot’s HDi common-rail direct injection technology FAP particulate filtering.
The 2.0 HDi FAP will already be familiar to SA motorists from its application in the 308, 3008 and 5008 model ranges. The 1 997 cc four-cylinder unit has a maximum power output of 120 kW at 3 750 r/min, while the flat torque peak of 340 Nm is achieved between 2 000 and 3 000 r/min.
The 2.0 HDi FAP is fitted to the 508 Active 2.0 HDi. This model is offered with a six-speed manual gearbox only.
A NEW HDI STAR
The newcomer to the HDi family – and the new star of the show – is the 2.2 HDi FAP powering the flagship 508 GT model. Despite its smaller capacity, the newcomer eclipses the previous 2,7-litre V6 turbodiesel in terms of performance, while achieving impressive gains as far as emissions and fuel consumption are concerned.
The 2 179 cc four-cylinder is equipped with a 16-valve cylinder head and twin overhead camshafts. Maximum power is an impressive 150 kW at 3 500 r/min, coupled to maximum torque of 450 Nm, sustained between 2 000 and 2 750 r/min.
A new-generation combustion chamber design, dubbed ECCS (Extreme Conventional Combustion System) allows the use of a slightly lower 16,0:1 compression ratio, which boosts performance and reduces both CO2 and NOx emissions.
The injection system employs piezo-electric injectors with eight apertures to ensure a finer spray of diesel, which in return affords more efficient combustion. The fuel supply rail operates at 1 800 bar, while the engine management system is controlled by new, high-performance ECUs.
Other innovations include hard-coated gudgeon pins and rings to reduce friction, which also benefits efficiency in the interests of lower fuel consumption and emissions, equivalent to more than 5 g/km of CO2.
VARIABLE GEOMETRY TURBOCHARGER
The engine’s variable-geometry turbocharger now features an impeller made from ultra-lightweight titanium, which reduces inertia and improves response to boost torque delivery at midrange engine speeds.
Overall refinement and noise levels have been improved through the use of twin balancer shafts, while the injection system has been specifically designed with noise reduction in mind. The result is smoother, more subdued engine note.
Another measure designed to reduce fuel consumption and improve efficiency is the so-called Voltcontrol system, which disengages the alternator under acceleration, but recharges the battery when decelerating or braking. Again, this equates to a CO2 reduction of almost 5 g/km.
Even the idle speed has been reduced from 820 to 700 r/min in the interests of improved day-to-day fuel consumption, while the engine also weighs 5 kg less compared to the previous-generation, less powerful DW12C unit it is based on.
TWO SUSPENSION CONFIGURATIONS
The Peugeot 508’s focus on refinement and efficiency extends to the suspension, which has been designed to confirm the brand’s reputation for exceptional handling and driving pleasure, while upping the ante as far as ride comfort and quality are concerned.
All 508 derivatives with the exception of the flagship 508 GT are equipped with an all-new MacPherson strut-type front suspension. This configuration finds a perfect balance between ride comfort and dynamic handling.
By reducing the weight of the front axle by some 12 kg compared to the 407’s design, the new front suspension achieves greater levels of refinement, benefiting overall comfort.
The 508 GT eschews the strut-type front suspension layout in favour of a drop-link dual-wishbone front axle. This layout allows bounce and steering functions to be decoupled, allowing high levels of steering accuracy and superior rigidity.
The dual-wishbone layout is better suited to the higher output of the GT version, as well as the sportier expectations and more dynamic driving intentions of the flagship’s target customers.
All 508 models employ the same multi-link rear suspension. It has been designed to combined efficient operation with maximum accuracy and effective vibration damping by decoupling longitudinal and transverse forces.
ADAPTIVE STEERING AND BRAKING
The 508 employs a rack-and-pinion steering system that is electro-hydraulically assisted. It continuously adjusts that assistance according to steering effort required, with more assistance at lower speeds.
Steering feedback is precise and communicative across the range, but the steering assistance is calibrated differently to suit the greater emphasis on sporty dynamics in the case of the 508 GT version.
The braking systems match the performance capabilities of the various 508 models. The all-disc arrangements employs 304 mm vented front discs, combined with solid 290 mm discs at the rear.
Again, the GT’s higher dynamic potential has necessitated an uprated braking system, with the fitment of larger, 340 mm vented front discs.