OFFERING Australia’s largest and cheapest – for now – diesel small-car sedan range are the twin lynchpins of the new Renault Megane X84 dCi series launched last week.

Priced from $27,990 for the manual Expression, the Megane dCi sedan comes in three versions – just like the continuing petrol model - and Renault expects to sell only about 30 units a month.

In line with most competitors, going diesel over the equivalent petrol variants invokes a circa-$3000 premium, with the top-line $35,990 Privilege diesel automatic adding $3500 on top of its petrol-powered equivalent.

Whether it is petrol or diesel, the auto costs $2500 extra in the Expression.

The Megane is the second Renault passenger car to offer diesel power in Australia, following the low-volume Laguna dCi hatchback launched late in 2006.

No Megane hatch dCi is on the horizon for now, as this model is built in France and would struggle to slip under the $30,000 barrier that the Turkish-sourced sedan easily manages.



“The Scenic diesel (due to debut at October’s Australian International Motor Show in Sydney) is for hatchback buyers,” said Renault Australia managing director Rudi Koenig.

In dCi automatic guise, that car will kick off at $37,990.

Renault claims it is late to the diesel party because it chose to wait until a fully automatic gearbox became available – a transmission choice that the diesels offered in the Ford, Mazda, Dodge and Citroen small-car competition currently make do without.

Despite the sharp price, the entry-level dCi sedan is no stripper special and easily eclipses its diesel-powered German and French rivals in the price-versus-equipment equation.

Stability control, six airbags, ABS brakes (with electronic brake-force distribution and brake assist), cruise control (with speed limiter), alloy wheels, climate control air-conditioning, built-in sunshades for rear seat occupants, a chilled storage box and a “clean hands” fuel filler system that reduces contact with dirty diesel bowsers all make the cut.

So does an advanced 1.9-litre common-rail turbo-diesel four-cylinder engine, using a multi-vane variable geometry turbocharger to help deliver 96kW of power at 4000rpm and 300Nm of torque at 2000rpm … if we are talking about the six-speed manual.

Like Holden’s AH Astra CDTi diesel, four-speed automatic Megane dCi buyers cop a drop in torque output in the name of smoother driveability and mechanical durability. In this case, torque slides to by 40Nm to 260Nm from 1600rpm.

Renault says that, while the power figure represents a 2kW fall compared to the 98kW/191Nm 2.0-litre four-cylinder petrol version, dCi torque output is up by 57 and 36 per cent respectively, depending on transmission.

The engine’s common-rail injection system uses pressure of up to 1350bar, for a better optimisation of air and fuel mix and distribution, which then helps lower CO2 emissions to 154g/km (manual) and 180g/km (auto). The equivalent petrol engines are 180g/km (manual) and 201g/km (auto).

Similarly, in contrast to the petrol sedan, the dCi manual’s 5.8L/100km fuel consumption combined cycle average represents a 30 per cent imporvement, or 20 per cent if you factor in the dCi auto’s 6.8L/100km.

The company’s figures suggest that the sedan’s 60-litre tank capacity should see the manual theoretically travel 1034 kilometres before a refill, and the auto 882km.

Renault says its engine features pre-injection combustion technology to reduce diesel engine rattle when cold, as well as balancer shafts in the cylinder block that limit noise/vibration and harshness factors significantly.

The dCi unit also incorporates an exhaust gas recirculation valve that allows burned exhaust gas to be mixed with incoming air at medium speeds, reducing the build-up of harmful nitrogen oxide pollution.

Besides a catalytic converter, an oxidising ‘pre-catalyst’ device is also installed, close to the turbocharger, to cut cold-start emissions.