The DS3 is Citroen's latest model to incorporate this family of engines. Equipped with a VTI 82 engine, also available at Citroën C3, develops 82 hp (60 kW) at 5,750 rpm and obtains a consumption of 4.5 l/100 km, with a displacement of 1199 cm3. CO2 emissions have been reduced to 104 g/km.
Puretch engines offer high performance, associated with very small greenhouse gas emissions. Its specifications forced a revolution in mechanical design, by stipulating a specific power of 50 kW (68 hp) per liter, with a strong improvement in engines efficiency. In addition, the Puretech engine should be lighter and more compact than its predecessors.
The increase in efficiency has been achieved thanks to a distribution with 2 heads in the head, with 4 valves per cylinder, directly operated through mechanical pushers, to achieve a better filling and performance. Admission and exhaust camshaft trees have a variable hydraulic draft continuously, to provide greater liking use in low and medium regimes and an optimization of consumption.
Another point to highlight is the reduced vibration and rumorosity of version VTI 82, achieved thanks to a counter -bass balance tree. Finally, electrical management allows optimizing battery charge with alternator free wheel, which is used to the maximum when it does not need to provide energy.
To achieve these results, the development has needed multiple evolutions, among which are: the reduction of the displacement (Downsizing), the choice of a three -cylinder engine compared to one of four, the reduction of the weight and a more compact design, the decrease in internal friction and the optimization of combustion.
52 patents have been registered for the realization of this new generation of engines; 23 Related to motor architecture, 20 with engine control and 9 on specific manufacturing procedures and tools.
Puretch, less displacement, but more performance
In addition to the improvements in pesos and friction, Downsizing technology allows fuel consumption and CO2 emissions to be reduced very importantly. Applied successfully in other gasoline and diesel motorizations, its use becomes more relevant in this range of engines. They will equip the lighter vehicles, contributing to reduce Citroen emission stockings.
The choice of a 3 -cylinder motorization over a 4 has multiple advantages: the reduction of friction losses, the decrease in the number of moving parts, the reduction of the weight or the compact dimensions allow to limit the consumption of fuel.
Thanks to the reduction of the number of cylinders and the redefinition of various mechanical organs, the decrease in weight, compared to replaced motorizations, is 25 kg for the VTI 68 engine, and 21 kg for the VTI 82 version, which is a reduction greater than 20%, for the engine mounted and without the accessories (alternator, starter engine ...).
The ass are light alloy, thanks to the use of a specific cast iron procedure called PMP or investment mold. The integration of different functions limits weight and dimensions. The exhaust collector is directly integrated into the cylinder head, allowing a reduction in the number of pieces and weight. The exit module of the cooling circuit as well as the upper motor support, integrated, are part of the pieces that leave directly from the Charleville foundry. Made in molten aluminum under pressure, the shirts of the cylinder crankcase are inserted during the foundry made in Mulhouse. This engine is more compact than the previous generation, with about 100 mm less width and 70 mm less height, including accessories.
The decisions taken The design of the PureTech engines family have led to modifications in several main pieces, to reduce mechanical friction losses, which represent about 20% of the power consumed by an engine. The main pieces or organs affected are the crankshaft, especially because of its dimensions and the decentralized of the shirts of the pistons. The axes of the pistons, segments and distribution pushers are equipped with low friction coating (DLC - Diamond Like Carbon) to limit friction. The regulated oil pump, with variable displacement, allows permanently to supply the optimal lubrication pressure, the friction associated with the operation of this pump have been reduced in this form by 30%. The wet distribution strap integrated into a crankcase, has a duration that equals that of the vehicle. This technology also contributes to its silent operation. These improvements make the Portech engine the new reference of the category in regard to friction, with a global reduction of the order of 30%.
The combustion system, the main element in consumption and emissions, allows most of most technologies embarked on the engine. The choice of the relationship between the diameter and the race has been determined to optimize the commitment between the intrinsic performance of the combustion system and the motor friction losses. Internal aerodynamics (admission ducts, shape of the piston and combustion chamber, with a compression ratio of 11 to 1) to allow the operation of the combustion system with strong IGR rates (internal gas recirculation or recycling or recycling of residual gases) that decrease consumption and emissions of polluting gases.
To reduce engine heating time, the “Split Cooling” system has been used. At first, with the cold engine, the cooling circuits of the cylinder block and the butt are separated, in order to optimize the increase in temperature. This presents 2 advantages: Decreases CO2 emissions, higher when the engine is cold and allows you to heat the cabin in a more efficient way. For maximum efficacy, the 3 -way catalyst is implemented from the engine output and is equipped with 2 probes.
Citroën C3 prices
PVP recommended Peninsula and Balearic Islands (VAT, Promotional Operation, Enrollment and Transportation Tax).
Maximum recommended price
Citroën C3 vti 68 Attraction 10,350 €
Citroën C3 vti 68 Tonic 11.480 €
Citroën C3 vti 82 Tonic 11.940 €
Citroën C3 vti 82 Collection 12.500 €
Citroën C-Elysée prices
PVP recommended Peninsula and Balearic Islands (VAT, Promotional Operation, Enrollment and Transportation Tax).
Maximum recommended price
Citroën C-ElySée Vti 72 Seduction 11,650 €
Citroën C-ElySée Vti 72 Exclusive 12,750 €
Citroën DS3 prices
PVP Recommended Peninsula and Balearic Islands (VAT, Enrollment and Transportation Tax).
Maximum recommended price
Citroën DS3 VTI 82 Design 15,330 €
