Alongside the New Twingo and the Clio Grand Tour concept, Renault also chose the 2007 Geneva Motor Show as the backdrop for the unveiling of its latest weapon in the battle for hot hatch domination, with the introduction of its first high performance diesel, the Megane Renaultsport dCi 175. Pricing for the new range has now been confirmed, starting at £18,950 and rising to £20,850.

The launch of the new Megane Renaultsport dCi 175 models completes the recent focus on higher performance models from FIA Formula One World Champions Renault, and in the case of Megane, gives it one of the most comprehensive medium-sized hot hatch ranges on the market.

In the last six months alone, the range of more potent, driver-focused Renaults has increased considerably. The Clio III range has been widened with the launch of the 138hp Dynamique S and 197 F1 Team R27 special edition, with a GT version due to follow later in 2007. At the same time, the Megane range spawned a “warm hatch” GT and the ultimate Renaultsport special edition, 230 F1 Team R26. Just on the horizon to complete the recent performance additions, is a GT version of New Twingo which will arrive in the UK in September to emphasise the new city car’s sporty credentials.

With the advent of diesel power, the Megane Renaultsport range now caters for every type of performance enthusiast, whether their preference is for the better fuel consumption and greater low down torque of a turbodiesel, or the cheaper initial purchase price and broader power spread of a traditional turbo petrol engine.

Already one of the most powerful two-litre diesel engines in the market, the 2.0 dCi flagship powerplant has been enhanced still further by Renaultsport’s modification of the throttle mapping to optimise response time. The result is that they have shaved a full second off the 50 to 75 mph time in second gear compared to the Renaultsport 225, down to 10 seconds.

This engine is packed with advanced technology, including a variable geometry turbocharger which provides a wide spread of torque throughout the rev range. Piezoelectric injectors are capable of operating up to five times per cycle, which helps reduce engine noise, fuel consumption and particulate emissions. Injection pressure has been set at 1,600 bar to optimise combustion and improve the fuel/air mixture. The engine is also equipped with an additive-free periodic regeneration filter, as well as two balancer shafts to keep noise and vibration levels down to a minimum.

Coupled to a six-speed manual gearbox, the smooth power delivery also belies impressive performance figures. Peak torque of 360 Nm arrives at 2,000 rpm, while the maximum 175 hp is available at just 3,750 rpm for effortless mid-range punch. The new flagship Megane engine also dispatches 0 to 62 mph in 8.3 seconds, before powering on to achieve 137 mph.

Built at the Renaultsport factory in Dieppe, the formidable new dCi 175 additions to the Renaultsport stable will also doubtless appeal strongly to drivers wary of the higher running costs sometimes associated with hot hatches, with impressive fuel economy on a combined cycle of 43.5 mpg and competitively low CO 2 emissions of 172 grams per kilometre.

In line with the revised range of Megane Renaultsport petrol models, the new diesel versions are available in two trim levels – dCi 175 or Lux, in three- or five-door hatch form, priced from £18,950 to £20,850. The new models effectively cost £490 more than the equivalent petrol versions.

Renault’s new diesel hot hatches enter a select group of high performance diesel hatches, including the BMW 120D five-door, SEAT Leon FR 2.0 TDI and VW Golf GT TDI 170PS. In three-door hatch guise, at £18,950, the Megane Renaultsport dCi 175 undercuts its BMW rival by £1,215, even without taking into account the Renault’s much higher specification. It also undercuts its Golf rival by £350 initially at £19,300 and by £620 once cruise control is factored back into the equation.

The list of standard equipment for the new Megane Renaultsport dCi 175 is as impressive as its performance: 17″ alloy wheels, 60W RDS radio single-CD with six speakers, air conditioning, alarm, cruise control with speed limiter, dark grey cloth upholstery with silver stitching, electric folding door mirrors, ESP with ASR traction control and CSV understeer control, leather steering wheel and gear knob, plus trip computer.

In addition to the core features of dCi 175, Lux trim adds identical equipment to the re-badged 225 Lux petrol model, which means it includes: 18″ alloy wheels, 60W RDS radio single-CD MP3 with six speakers, climate control, electric folding mirrors, full dark carbon leather upholstery, Hands Free Renault Card for ignition and entry, metallic paint and tyre pressure monitor.

Visually, the only difference between the petrol and diesel Megane Renaultsport versions is the lack of rear spoiler on the dCi 175, otherwise the lowered stance, subtle bodykit and twin central exhaust pipes remain. Inside, the mood is distinctly sporty thanks to the aluminium pedals, leather steering wheel and seats with increased lateral support.

Drivers of high-performance diesels tend to cover much higher annual mileage than those in petrol-powered equivalents. For them, therefore it is vital to strike a balance between running costs, performance and compliant ride and handling when it comes to choosing a new car.

As a result, while the dCi 175 shares some of the underpinnings taken from the Megane Renaultsport petrol models, it also features some distinct alternations, such as the use of Continental Sport Contact 2 tyres.

Independent steering-axis front suspension guarantees precise and efficient handling in all circumstances, while body movement is minimised by a 20mm-diameter anti-roll bar. The front suspension has also been tuned to suit Megane Renaultsport dCi’s features and weight distribution. Spring stiffness and damper settings are consequently specific to this diesel version, enabling the car to retain an agile and responsive nature, but one which is still nevertheless capable of soaking up long distances with ease. The rear suspension is based around a programmed-deflection flexible beam, the torsional stiffness of which is equivalent to that of the Cup versions of Megane Renaultsport.

A Cup chassis will be available as an option in the UK for both dCi 175 versions at a later stage for the more enthusiastic driver. When it arrives, it will feature an ESP system that unlike the standard system on other Megane Renaulsport models, can be switched off, as well as specially-tuned front and rear dampers and 37% stiffer springs compared with the standard sport chassis version.

Powerful and fade-free, the Brembo braking system features four discs that are impressive in terms of both diameter (312mm and ventilated at the front, 300mm at the rear) and thickness (28mm at the front, 11mm at the rear). The front discs are also equipped with four-piston calipers. The alloy wheels run on Continental Sport Contact 2 tyres, either 225/45R17 (dCi 175) or 225/40R18 (dCi 175 Lux). These were chosen for their renowned qualities of traction and grip. The electronically-variable power steering has been specifically calibrated to suit the car’s weight distribution.

In terms of active safety, Megane Renaultsport dCi is fitted as standard with a dynamic electronic stability programme (ESP) which has also been set up to suit the car’s particular characteristics. Passive safety features are the same as those on any other Megane – a five-star performer in Euro NCAP crash tests.

Insurance groups for the new dCi 175 versions are impressively low at 12E, five bands below the petrol models in the Megane Renaultsport range. Full pricing for the expanded range follows below:

dCi 175 Sport Hatch: £18,950
dCi 175 Lux Sport Hatch: £20,350
dCi 175 Hatch: £19,450
dCi 175 Lux Hatch: £20,850
225 Cup Sport Hatch: £18,960
230 F1 Team R26: £19,860
225 Lux Sport Hatch: £19,860
225 Lux Hatch: £20,360

The Megane Renaultsport range now consists of eight models, available in either three-door Sport Hatch or five-door Hatch variants, ranging in petrol and diesel power from 175hp to 230hp.

Within the range, buyers still retain the choice of opting for the more stripped-out 225 Cup version with its reworked chassis and suspension set-up, the more luxurious and grand tourer-oriented style of the original 225, or the ultimate expression of Renault’s Formula One knowledge in a road car with the 230 F1 R26 special edition and its limited slip differential, revised Cup chassis and 5hp power increase.

The Megane Renaultsport R26 has already caused quite a stir among the established hot hatch elite, most recently in a comprehensive group test in Autocar magazine, where it left a field of 13 other hot hatches trailing in its wake, on both road and track. “It accelerated like a rocket, stopped on a sixpence, turned in, gripped. And then disappeared over the next horizon. Physically, metaphorically…you name it, the Megane did it for us. Which is why it wins this contest, and then some.”