The name Renaultsport brings with it a pretty impressive history of sporting cars.

Renault’s ‘excitement department’ made its name with the Clio, starting with the go-kart-like 172 and moving on to the 182 variations, the completely bonkers mid-engined Clio V6 and the latest Clio 197. More recently, it turned its attention to the larger Megane and has won praise for the 225 and 225 Cup.

Any new Renaultsport car has big boots to fill, especially when it’s powered not by high-octane petrol but by diesel.

The Megane Renaultsport dCi 175 is the first diesel car to wear the Renaultsport badge and promises the thrills and excitement expected of the name, but with the fuel economy and low CO2 emissions of a diesel.

Power comes from Renault’s 2.0-litre dCi engine developing 175bhp and 265lb-ft of torque, which means 0-62mph in 8.3 seconds and a top speed of 137mph. That might not sound spectacularly quick, but the 50mph to 75mph acceleration time is a second quicker than the petrol Megane 225. The engine has also been remapped to give a quicker throttle response.

The claimed combined fuel economy is 43.5mpg, while CO2 emissions are 172g/km.

With a P11d price of £18,732 for the three-door version, and a benefit-in-kind (BIK) tax bracket of 24% that means a monthly company car tax bill of £82 for a 22% taxpayer. By comparison, a three-door petrol Megane 225, priced at £500 less, will cost the same taxpayer £97 a month thanks higher emissions which put it into the 27% BIK band.

On sale now, it comes with a sportier chassis and tuned suspension aimed at agility, while still being bearable on long journeys.

A more extreme, harder Cup chassis will be available as an option later in the year, which will feature stiffer springs and an ESP stability control system which can be fully turned off, no doubt much to the delight of fleet managers!

Visually, the Renaultsport dCi is the same as its petrol-engined brothers. The bodykit, lowered suspension and twin central exhausts remain, while inside there are the usual aluminium-effect pedals and more heavily-bolstered sports seats.

Two trim levels are available – standard and Lux. Standard includes 17-inch alloy wheels, air-conditioning, leather steering wheel and ESP. Lux trim offers 18-inch wheels, climate control, full leather and hands-free entry and ignition, as well as metallic paint and a tyre pressure monitor.

As it’s the first Renaultsport to be powered by diesel, Renault isn’t entirely sure of sales volumes for the car. In the first quarter of 2007, it sold about 400 Renaultsport Meganes in the UK and, Europe-wide, Renault expects diesels to make up half of all the range sold.

James Mitchell, Renault UK brand manager for Megane, said: “Because it’s the first diesel product, it’s difficult to know whether we can perform as strongly as the petrol range.

“We’re testing the water and looking at what premium there is for a Renaultsport product over a standard Renault product in terms of residual values.”

Behind the wheel

The RS dCi certainly looks the part, sitting purposefully on its big wheels and lowered suspension. However, hit the starter button and the sporty rasp you’d expect from a Renaultsport petrol car never materialises.

Conversations with the development team reveal that trying to make a diesel car sound like a petrol model is a fruitless task, and despite the claims of the PR department it’s easy to tell what fuel the engine is running.

I tried the Sport chassis first. Around town and on the motorway the car feels perfectly at ease – like a common-or-garden diesel Megane, in fact. Where this car is meant to shine is in the twisty bits, where driving enjoyment is a priority. The chassis is pretty good, although not outstanding.

Push it into a bend and there’s plenty of grip and it’s nimble enough, although it never feels truly involving. The seats aren’t great – I felt like I was perched on it rather than held in, in the way a sports seat should.

The Cup chassis is much better, although we’re not likely to see it on UK shores for a while yet.

There’s even more grip and it feels alive through the bends, yet still feels entirely at home on the motorway. And it comes with much better seats, too. However, the competence of the chassis serves to highlight the problem with the engine – despite a fairly responsive throttle it’s just not dramatic enough to cut it in the world of hot hatches. In trying to compromise between performance and frugality, it errs on the side of caution and is never more than warm.

The RS dCi is a good car. It’s pretty nippy, comfortable and feels more than adequate on B-roads. But is it deserving of the coveted Renaultsport badge? I have my doubts.

Fact file

Model: Megane Renaultsport dCi 175
Max power (bhp/rpm): 175/3,750
Max torque (lb-ft/rpm): 265/2,000
Max speed (mph): 137
0-62mph (secs): 8.3
Fuel consumption (mpg): 43.5
CO2 emissions (g/km): 172
On sale: Now
Prices (OTR): £18,950 (3dr) £20,850 (5dr)