This is essentially Renault's answer to VW's Polo BlueMotion, except that it's still a concept rather than an already available product.

Of course, the Logan is built by Renault subsidiary Dacia in Romania so it may be able to better compete on price if/when it goes into production.

3.8 L/Km = 62mpg (US). Ought to be a market for that.

Would be easy to use modern developments to get 100+mpg.

Spare us the re-invention of the wheel.

Am I getting impatient?

You bet!

B100 is not hard for a diesel engine, what so great about B30?

A handful of bits of plastic adding up to about £50 in total reduced the Cd from 0.36 to 0.29.

It makes me so mad that the car industry can do such simple and cheap things like this but choose not to bother.

Back in the 70's, French government broadcast an ad to promote its alternative energy policy (nuclear among others..): "en France, on n'a pas de petrole mais on a des idees" (in France, we do not have oil but do have ideas).
Taking the current situation, this motto should be refreshed and apply on the international stage. Not sure that would be so difficult?

"A handful of bits of plastic adding up to about £50 in total reduced the Cd from 0.36 to 0.29.

It makes me so mad that the car industry can do such simple and cheap things like this but choose not to bother."

the placement and configuration of the bits of plastic is crucial to get the desired effect, so thorough wind tunnel testing is required, so the cost is not just the £50 for the splitter and v-generators, but yes, generally aerodynamic improvements are a relatively cheap way to improve performance/economy.

@ Clett -

the question is not just how much fuel economy gains cost to develop and produce but how much extra the customer is willing to pay for them. Car makers are for-profit businesses.

Traditionally, the most effective strategy for increasing revenue per sale and therefore profits has been to add more power, more space, more luxury, more style, more safety. Car makers had to learn to love that last one, but in the end all of these features are benefits that accrue primarily to the owner.

Meanwhile, most consumers do appreciate the need for clean air, reducing CO2 emissions, improving energy security etc. and, they are willing to pay a little to do their bit. Any fuel savings translate do accrue directly to the owner, the main reason why diesels are so popular in Europe.

However, the primary connotation of "saving fuel" is still "penny-pinching", so to some extent this vehicle choice advertises that the owner simply couldn't - or else chose not to - afford a car with higher performance. Profit margins on econoboxes are low, so European car makers are careful to position their thriftier models as good for the environment - an emotional appeal - rather than as easy on the wallet.

Other than fuel cost, the benefits of greenery accrue to society as a whole. Consumers therefore do not consider them premium features and won't pay extra for them unless they either have to by law, are shamed into compliance or, society offers financial incentives such as tax breaks and co-pays. No-one wants to be the sucker that paid more for less just so the neighbor can buy himself a polluting or gas guzzling vehicle.

This aversion to free riders is perhaps particularly strong in Europe, but it exists in the US as well. It is ultimately the reason why fleet average fuel economy isn't coming down and why especially green models - like the concept discussed in the article - tend to do poorly in the market. Consumers simply aren't particularly altruistic when it comes to buying big-ticket items like cars. However, all is not lost.

For example, BMW decided to make its high-falutin' Efficient Dynamics package a standard feature of virtually every model they produce, as part of the regularly scheduled product line refreshes. It's really just a stop-start system with a slightly beefier lead-acid battery, more intelligent control of the alternator load and an electric water pump. The company could never have achieved sufficient unit volume had it chosen to make the package merely an available option. However, perhaps by fortunate coincidence, they are also addressing the free rider problem: because it's standard equipment, virtually all buyers of these luxury vehicles can claim it's part of their bit for the common good.

Btw, Citroen is doing much the same with its C2, C3 and C4 models.

Conclusion: car makers won't have much luck selling especially green models, except in California where the combination of celebrity cult and techno-geekery has made them very fashionable. Elsewhere, the key is to elevate the whole brand image (a.k.a. general margins) by offering modest improvements as standard features across the product line. This actually also yields the greatest bang for buck in terms of the benefits to society as a whole, but it is a harder (i.e. less profitable) sell than traditional premium features.

The Logan is a comfortable car but rather "boxy" and ugly by the way, it`s hard to believe the Cx reduction from 0.36 to 0.29.
If those things like spoilers and vortex generators works so well it will be the paradise for the "tuning" market.
I think that the most important modification in aerodynamics in this car is the "inlet air flux reduction", better saying "inlet air flux management" because it depends on the car demand of power and cooling, the car speed and temperature of inlet air.

Hi Mario, it is hard to believe that a "boxy" vehicle can have an excellent drag coefficient. Please consider the following example.

The slick, sexy Dodge Viper's drag coefficient is a dismal 0.40. On the other hand, the dumpy-looking Toyota Yaris claims a superb Cd of 0.29!

Attention to small details like that probably explain why Chrysler (plus Ford & GM) are taking a drubbing in the marketplace, while Toyota can't make their stuff fast enough!

Driven my Audi A2 1.2 TDi for over 5 years now. 81g/km CO2 and 93 (UK) mpg. Even on autobahn at 90mph she'll return 66 (UK)mpg all day long.

So where is the progress?

Why aren't standard cars produced with low friction tyres, better Cd values and lighter body weights?