You may have noticed that car manufacturers now tend to boast about the low emissions and fuel economy of their cars – not their unbridled, class-leading performance. The reasons for this are obvious – market forces, public concern about the environment, and new emissions legislation.

What is more interesting is how successful car manufacturers are being at producing models with great fuel economy and low CO2 emissions. Over the last couple of years, most of the major car manufacturers have introduced specific branding for their low emissions/fuel efficient models, highlighting the most environmentally-friendly cars in their ranges.

Here are a few examples of badges you may have seen around:

• ECOnetic (Ford)
• ecoFLEX (Vauxhall)
• EfficientDynamics (BMW)
• Bluemotion (Volkswagen)
• eco2 (Renault)
• Blue Lion (Peugeot)

All of these badges are used to denote standard models that have had a package of modifications made to their normal specifications, with two aims – saving you money and saving the environment:

• Lower CO2 emissions – resulting in a lower car tax band
• Improved fuel efficiency – an obvious attraction, especially at the moment!

Does It Really Work?

Yes. The claimed emissions and fuel economy figures for these models are pretty impressive and many of them are nearly achievable, assuming a reasonable mixture of journey types and a careful, fuel-efficient driving technique.

I know someone with a Ford Focus ECOnetic and without much effort, he can average 55mpg. Noted car expert Honest John also reported that he averaged more than 56mpg over 3,000 miles in his Ford Focus ECOnetic test car in real world driving conditions, including urban driving, traffic jams, rural roads, steep hills and photo shoots (not sure about that last one…).

How Does It Work?

Each manufacturer does things slightly differently but there are a number of popular approaches to optimising fuel consumption and emissions. Some cars use more of these techniques than others:

• Adjust the gear ratios – making top gear in particular a bit higher, so revs are lower at motorway speeds, saving fuel
• Fit extra aerodynamic bodywork to reduce drag, including panels under the car
• Save weight by using lightweight materials and not including a spare wheel
• Choose low rolling resistance tyres, such as Michelin’s Energy Saver car tyres
• Adjust engine tuning to reduce power and concentrate torque at low revs, reducing the need to rev the engine so much – high revs use more fuel
• Automated start-stop systems that cut the engine when you are idle in traffic and then restart it as soon as you put the clutch down
• Low-friction oils (yes, really)
• Gear shift indicators to help you change gear at the optimum time
• Regenerative braking systems that store energy created during braking and then use it to reduce the load on the alternator, which saves fuel (getting a bit technical here, I know – apologies)

If you’ve read this far, you’ve probably got the idea by now – by tweaking a load of things, car manufacturers can optimise their designs for low emissions and fuel efficiency. I am certain that these techniques will gradually become standard – just like catalytic converters are today. It wasn’t so long ago that some car manufacturers fitted a badge to models with catalysts, boasting about their environmental credentials!

Should I Buy One Of These ‘ECO’ Models?

Why not? You’ll enjoy lower (possibly even zero) road tax and lower fuel bills. I would probably buy one if I was in the market for a new car at the moment. Most of the models on offer are diesel, but if you are happy with that then you will find that despite their lower emissions, they still offer decent performance and good interior specification.

It’s the shape of things to come, that’s for sure.