WALK into a car showroom tomorrow and you could buy a vehicle that parks itself, or one that warns you if you’re about to crash. You could find one with a display that shows you the road ahead despite the thickest fog. Next year there could even be a car you can drive into the sea and race through the waves like a speedboat. So why can’t you buy a car that can go 100 miles on a gallon of fuel?
There is certainly no shortage of people who would jump at the chance to own one: according to a recent poll, almost two-thirds of Americans would love a car with this kind of thriftiness. Doubling a car’s fuel efficiency doesn’t just save you money at a time of soaring oil prices, it also halves the vehicle’s planet-warming CO2 emissions. Yet in the US – the world’s largest market for cars – there has been little improvement in fuel efficiency for decades.
So there was good news in December 2007, when President George W. Bush signed a new US energy bill into law. The new act demanded an increase in the fuel efficiency of cars and light trucks by 40 per cent, to an average of 35 miles per US gallon – the first increase since 1975. Though it doesn’t come into force until 2020, it was hailed by many in Congress as a historic development. Even environmental groups gave the news a cautious welcome.
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At the same time the US car industry is under pressure from 17 states that would like to impose their own strict emissions limits on all new vehicles – the same tough “clean car” standards that were mooted by California back in 2004. Although the federal Environmental Protection Agency insists that no state is allowed to set stricter standards of its own, that ruling is now being challenged in the courts.
Whatever the result, US citizens are likely to be buying a very different breed of car five years from now. Besides the stick provided by the new energy bill, car makers also have a tasty carrot to chase. With a pot of $10 million for the winners, the Automotive X Prize – announced in 2007 – is designed to change the face of the car manufacturing industry. The idea is to stimulate the production of affordable, desirable high-performance vehicles that can drive at least 100 miles on a US gallon of fuel (42 kilometres per litre), emitting around 60 grams of CO2 per kilometre.
It is not simply a technological challenge. There are already a few cars fuel-efficient enough to meet these tough emissions standards. The problem is that if the only cars that fit the bill are ugly, expensive or offer low performance – or all three – most people will stick with what they’ve got, thank you very much. And even optimists admit that fuel-cell-based and all-electric cars are probably a decade away. So the big question is, can you create an attractive but inexpensive vehicle based on an existing engine design that packs a punch but doesn’t cost the earth?
The answer is yes, you can – it’s already happening in the European Union. Here a typical mid-sized car manages about 38 miles per US gallon. The EU is considering new legislation to ensure that every new car rolling onto its roads will emit no more than 130 grams of CO2 per kilometre, corresponding to a fuel effiency of about 42 miles per US gallon. Although some manufacturers – notably Land Rover in the UK – are lobbying against this limit on the grounds that it is too restrictive, the target is plainly achievable. “You can even buy a BMW 3 Series that releases 130 grams per kilometre,” says Paul Nieuwenhuis of Cardiff University in the UK. “It’s doable, and with quite acceptable cars.”
Nieuwenhuis has just completed a report for the European Commission which examines the range of innovations that could bring greener cars onto the road. He spoke to component manufacturers – the car-makers’ suppliers – who said there were actually plenty of options. “None of them wanted to be named in the report,” Nieuwenhuis says, “but they said the car manufacturers were bullshitting: quite a bit can be achieved with existing technologies.”
Simply replacing petrol with diesel can make a significant difference, for example (see Diagram). A recent study by Norwegian researchers Karl Høyer from Oslo University College and Erling Holden from the Western Norway Research Institute in Sogndal on for a range of fuels (see Chart) suggests that switching to new, cleaner diesel engines can reduce CO2 emissions by as much as a quarter. Better still, a hybrid vehicle that can use either its diesel engine or its battery for propulsion would generate about two-thirds the CO2 emissions of existing petrol-powered cars. Last year, Peugeot announced plans to have a diesel hybrid on the market by 2010.
A simpler measure is adding a “stop-start” system that cuts the engine when the car is stationary, then fires it up again as soon as the driver touches the accelerator. In fact, this is already on the market; Citroën has been using it on some models for a couple of years. The system can be incorporated into any new vehicle design, and even be retrofitted. The new BMW Mini Cooper Diesel, launched in October 2007, uses it, cutting between 10 and 15 per cent off CO2 emissions.
This lifts the Mini’s fuel efficiency into the same league as the Toyota Prius, a hybrid car that can be driven by its petrol engine or its electric motor, or both. This parallel arrangement gives it good fuel efficiency – it releases just over 100 grams of CO2 per kilometre – even though the complex system adds weight, and heavy vehicles use more fuel. A more promising option may lie in “series-hybrid” cars where a small combustion engine, running almost continuously at optimum efficiency, drives a generator which in turn feeds an electric motor that turns the wheels. Unused electricity tops up the battery.
Electric motors can provide the torque needed for rapid acceleration and they are several times more efficient than combustion engines. The General Motors Chevrolet Volt concept car, for example, has a 1-litre petrol combustion engine that has no connection to the drive train, but simply powers a 53-kilowatt generator that drives the motor. GM claims this arrangement can manage at least 150 miles per US gallon of fuel.
The Volt boasts a range of energy and carbon-saving technologies that are being touted as the way forward for greener auto design, including lightweight body panels, regenerative braking, lithium-ion batteries and the ability to use bioethanol as well as gasoline (see Diagram). Putting all these into a concept car, however, is not enough to save the planet, says the X Prize Foundation, which offers the Automotive X Prize.
The AXP was conceived with a similar aim to the foundation’s aerospace prize, won in 2005 by space-flight pioneer Burt Rutan: it is designed to stimulate an otherwise stagnant industry. Neal Anderson, one of the senior directors of the AXP, talks about breaking the “bottleneck of innovation” that has hit the US auto industry. US cars and light trucks are responsible for 45 per cent of the world’s vehicle emissions. Since manufacturers have failed to do much to improve fuel efficiency, the AXP aims to give them an incentive.
A recent poll by the X Prize Foundation revealed that 62 per cent of Americans want to buy a car capable of 100 miles to the gallon. That’s a good start, but how much are they willing to pay for it? The AXP’s multimillion-dollar payout is on offer for a car that can exceed that fuel efficiency and is also desirable and affordable. In fact there are two prizes. One is for a “mainstream” vehicle capable of carrying at least four people, and the other for an “alternative” two-seater. Speed and acceleration will also matter. In short, not only must the cars’ green credentials be impeccable, but the vehicles must also be attractive to investors.
So how hard can it be to produce a desirable, efficient, low-emissions, high-performance car that can be mass-produced and sold at a reasonable price? It is a tall order, says John Heywood, director of the Sloan Automotive Laboratory at the Massachusetts Institute of Technology. “There is a sense within the auto industry that the market is not yet showing lots of interest in paying more and reducing fuel consumption,” he says. “There is better technology out there, but it costs more. Bits of it come for very little, but not the big bits, and the costs rise as you get better solutions.”
One of the obvious ways forward involves reducing vehicle weight: make the car lighter and it’s easier to accelerate, and there’s less work to do against gravity when you drive uphill. A lighter car also has less “rolling resistance” from its tyres, though this raises safety issues (see “Losing their grip”). Cutting a car’s weight has cost drawbacks too. “Weight reduction is surprisingly expensive,” Heywood says. “The propulsion-system improvement you get in a hybrid is more cost-effective than weight reduction.” But if you are willing to spend the money, there are options. Some car-makers have moved into producing vehicles with aluminium bodies, for example, though these are typically high-end cars: aluminium is expensive both to buy and to use as it requires manufacturers to switch to unfamiliar fabrication techniques. Carbon composites are another option. They can help with aerodynamic styling because they are shaped easily, but can cost as much as 100 times more than steel.
Some composites companies claim that this expense is a mirage, however. While switching from steel would be expensive for a large, established car-maker, a small firm starting out in the auto business and using only composites faces a tiny fraction of those capital costs, says Steve Cousins of Axon Automotive, a green car company based in Wellingborough in the UK.
Axon, which will compete for the AXP, has patented a mass-production technique to make a range of structural elements and body panels from carbon composites. The products are made from carbon fibre “ropes” each braided over a foam core and infused with epoxy resin. The company claims they are as strong as steel but only 40 per cent of the weight. Cousins points to developments in Japan as evidence that the auto industry is moving towards composites. In early October 2007, the Japanese firm Toray, which supplies carbon composites for Boeing’s Dreamliner aircraft, announced it was planning to invest 20 billion yen ($182 million) in its car-parts division. At the Tokyo motor show later that month, Toyota unveiled a Prius concept car made with a carbon-composite body.
Cousins claims that carbon composites could even destabilise the auto industry, allowing smaller companies to threaten the majors (see “Power struggles”). The fact that Google and Swatch – which originated the smart car idea – have both invested in the green car industry is no coincidence, he says. “It signifies a trend: companies outside the industry will be responsible for major innovation,” Cousins says. “There is an opportunity for 20 or 30 companies to enter the market in Europe and the US.”
Heywood is not convinced. “The technology in vehicles is very sophisticated, very robust and very cheap,” he says. “Newcomers will have a difficult time getting a foothold and becoming significant players.” This is a fundamental problem for the AXP, he says. The competition will produce concept cars – helpful ideas – but nothing that changes the marketplace. It has far too simple a view of the industry and how its products get bought.
Nieuwenhuis disagrees. The AXP is encouraging a trend that had already begun, he says: many people are choosing smaller cars, going for style rather than out-and-out performance. Speed restrictions and traffic congestion mean that today’s cars are far more powerful than they need to be, he says. As long as people can accelerate sharply enough to overtake at between 60 and 100 kilometres per hour – and feel they look good in their car – they will happily reject the traditional “big is beautiful” automobile ethos. Nieuwenhuis reckons companies that recognise this are already reaping the benefit. “People pay quite a lot of money for a Mini. I can see a future where luxury cars become smaller and lighter, but still command a premium in the market.”
“The industry is vulnerable to disruptive innovation by cheaper, simpler cars”
Power struggles
A number of US states, including Vermont, would like to impose stricter emissions limits on new vehicles and have taken their fight to court. In September 2007, a Vermont judge ruled against the car manufacturers. “It is improbable,” said Judge William Sessions, “that an industry that prides itself on its modernity, flexibility and innovativeness will be unable to meet the requirements of the regulation, especially with the range of technological possibilities and alternatives currently before it.” Sessions doubtless had a little grin on his face when he added that “history suggests that the ingenuity of the industry, once put in gear, responds admirably to most technological challenges”.But the US auto industry complains that any legislation to limit greenhouse gas emissions could add as much as $10,000 to the price of some types of car. In Europe, companies such as Land Rover are similarly hostile to proposed legislation on emissions. That’s because the legislation doesn’t fit with many of the companies’ business models, says Steve Cousins of Axon Automotive in Wellingborough, UK.Cousins has shown that car-makers’ profits are reliant on producing ever more powerful vehicles. Their financial sustainability broadly depends on steadily producing more expensive vehicles, but the only thing consumers are willing to pay more for is more power ().In the early 20th century, engineers were struggling with this because adding power was expensive, and that extra power came in small increments. These days beefing up comes easier – average peak engine power has increased consistently in the last 30 years. The price per unit of power has stabilised too. Cousins and his colleagues have calculated that from 1970 to 2005, the price of cars in pounds sterling effectively scaled according to the simple equation price = (150 × brake horsepower) – 2464.Fuel efficiency has also increased over the decades, but not to the same extent, and with more cars on the road than ever, with bigger engines than ever, the emissions problem is becoming acute. That’s because CO2 emissions depend not only on fuel efficiency, but also on the total amount of power on the roads. They also depend on how long cars spend on the roads, of course, and time spent driving has also increased. In short, it’s all bad news.On the current trajectory, CO2 emissions will double by 2020 as the total power on the roads goes up. If you want to reduce CO2 output, you have to reduce the power output. And that’s the opposite of what people will pay for – unless they are given an attractive alternative, that is.Right now, says Cousins, we are in a classic oversupply situation. Cars are much better and more luxurious than we need them to be. That makes the industry vulnerable to “disruptive innovation” by cars that are cheaper and simpler. The airline industry went through a similar process: in the UK, for example, high-end carriers like British Airways suddenly found themselves in fierce competition with “no frills” airlines like EasyJet. When new legislation starts to bite, we may see an EasyJet equivalent pop up. Perhaps one of the smaller companies already hovering around the edges of the market will produce a basic but comfortable car that – to everyone’s surprise – grabs a disproportionately large share of sales.
Losing their grip
At the Frankfurt motor show in Germany last September, Michelin trumpeted its “low rolling resistance” (LRR) tyres, which allow a car to use less power to move. Overcoming rolling resistance accounts for one-fifth of a car’s CO2 emissions, and Michelin claims that sales of its LRR tyres so far – 570 million tyres in 15 years – amount to a reduction of 2 million tonnes in CO2 emissions through a saving of 9 billion litres of fuel per year. But the idea also rings alarm bells because lower rolling resistance should mean lower friction – and longer stopping distances.Current LRR tyres use silicic acid in the tread surface, which changes the physical properties of the rubber. It was introduced in the 1990s to replace some of the carbon blacks in tyres. Engineers had claimed it reduced braking distances compared to standard tyres, while reducing rolling resistance by about a quarter. But according to research reported in November by one of Michelin’s competitors, Continental, based in Hannover, Germany, LRR tyres have a braking efficiency about 10 per cent lower than standard tyres. To illustrate, imagine two cars travelling at 100 kilometres per hour. With the brakes slammed on at the same time, the car with LRR tyres will still be travelling at 35 kilometres per hour as the car with normal tyres comes to a halt.Holger Lange, a tyre developer at Continental, reckons rolling resistance could be halved over the next 30 years. Though this would reduce fuel consumption by a further 10 per cent, achieving it while maintaining safety will be a significant challenge. Paul Nieuwenhuis of Cardiff University in the UK agrees. “The more grip you have, the more resistance you have – there is a limit to what you can do,” he says. “Innovative tread design helps, but it’s always going to be a compromise.”Continental say that developing tyres in this direction risks running counter to the European Road Safety Charter, which commits the EU to halving its number of traffic fatalities to 25,000 by 2010, but Michelin insist that safety doesn’t have to be a casualty with LRR tyres. In 2005 the independent auto consultants TÜV, based in Germany, tested a variety of tyres and found that the Michelin HP Primacy LRR tyre showed a shorter wet-weather braking distance than the average distance of five competitors’ tyres.
