31 Aug 06
A completely zero-emissions car is still some way off - but we're getting there...
Progress towards making more environmentally-friendly cars may seem frustratingly slow, but in the automotive industry, it's often the smaller, less headline-grabbing advances which can prove the most significant.
The Holy Grail of the practical, user-friendly, reliable and, most importantly, affordable and commercially-viable zero-emissions vehicle is still some way off, but there are a number of year-on-year improvements, trends on the horizon and exciting developments which are realistically achievable in the near future.
Much of this is being driven by ever-more stringent legislation on emissions and consumption, and increased pressure in commercially-important car markets such as California and Canada as well as from the European Union, and car makers are being strongly encouraged to clean up their acts and offer more efficient, cleaner vehicles - quickly.
Don't underestimate the impact of enhancements to existing petrol and diesel engine technology: the good ol' internal combustion engine has a lot of life left in it yet. The average new car sold in the UK today is far, far cleaner in terms of the emissions it pumps out than its equivalent twenty, or even ten, years ago. Credit developments such as multi-valve engines, variable valve timing, catalytic converters and more advanced electronically-controlled engine management, for a start.
Improvements are particularly notable for diesel-engined cars: although diesels have long been credited with better consumption levels and lower carbon dioxide output, they have fallen short in terms of other emissions, such as nitrogen oxides and harmful particulates - unburnt byproducts of the combustion process, or the black smoke often spotted coming from a diesel's tailpipe. But in recent years, not only have diesels improved immeasurably in terms of performance, refinement and general driveability, their fuel consumption is ever better and emissions ever lower.
