MIT prof sees no free ride to cleaner cars

To get under the hood of transportation technology, just talk to John Heywood.

Heywood, a professor of mechanical engineering at the Massachusetts Institute of Technology, and his colleagues took the proverbial big-picture view of transportation in a recent report on how the U.S. could slash gasoline usage by 2035.

John Heywood, MIT professor and transportation technology expert

(Credit: MIT)

Looking at the pace of technology development and the market "pull" of consumers, the report tries to sort out dead ends from more promising routes.

MIT's report concludes there's great potential for transportation technology. If lightweight hybrids and plug-in hybrids, for example, were the primary vehicle by 2035, the U.S. fleet would use about half the fuel it currently uses, helping significantly lower greenhouse gas levels.

Battery-powered cars aren't the only route to reinventing cars. Biofuels are touted as a gasoline replacement but are coming under more fire for financial and environmental reasons.

Hydrogen fuel cell vehicles remain the elusive prize--technically elegant yet stubbornly hard to make commercial and environmentally sustainable.

Meanwhile, smaller cars would go a long way to efficiency but automakers tend to build bigger and bigger cars, responding to consumer demand.

CNET News spoke to Heywood about the best transportation options for consumers and the country. For individuals, he says, our choices matter--buy fuel-efficient cars and don't drive aggressively if you'd like to clean up your ride.

But when it comes to big changes in transportation, he says that policies that encourage consumers to buy "green" are the only way to truly transform the nation's fleet.

Q: It seems the big conclusion from your report is that there are multiple pathways to cleaner transportation but it's not necessarily going to be easy to improve efficiency?
Heywood: You're right, there are a number of options. They haven't happened already because they cost extra to improve the efficiency of vehicles. And in a sense, the bigger the improvement the more the cost--does it pay off? Issues like this have slowed down our progress in the past.

Then there are some behavioral issues that are sometimes built into the system: We all like cars that are more fun to drive. More fun gets translated into more powerful (heavier) cars, so the market pulls ever-more powerful cars. The industry competes on providing the next car that's more powerful than the last one. That's been very detrimental to using better technology to directly reduce fuel consumption.

Do you get the feeling that there's a real push among at least a significant portion of consumers for more fuel-efficient cars? I'm not sure if people are willing to give up big cars necessarily, but do you get the sense that consumers and the industry are committed to more efficient technologies?
Heywood: Well, everybody wants it. The challenge is it doesn't come free. I have lots of discussions with friends and the broader public, and they ask, why don't cars get 50 miles per gallon? Well, you can have 50-mile-per-gallon cars, but they don't look like the cars that most people have been buying over the last few years, for example, because the bigger, the heavier, the more fuel it's going to consume to drive in the way that we want to drive. So there's sort of constrained opportunities, and that's what we have trouble relating to.

An MIT study lays out which technologies have the potential to be the most fuel efficient.

(Credit: MIT)

Looking at all the constrained opportunities, which one seems like the easiest path to go down--just improving existing engines versus plug-in hybrids versus clean diesel, etc.?
Heywood: We're seeing evidence right now as petroleum prices have gone way up over the last six months to a year. We've seen that what the buying public is doing is shifting down the size spectrum. So the really big vehicles, the sales are down significantly. At the small end with smaller vehicles, the demand is up significantly. There's a long waiting list for the limited number of hybrids that are now available. So that will start to pull bigger numbers for existing hybrid vehicles and pull new hybrid models into the market. The auto companies are scrambling to both improve standard engine transmissions and also to develop some of these alternatives that are significantly more efficient.

There's also a weight reduction from the vehicle by substituting lighter materials. The more use of aluminum instead of steel or high-strength steel instead of standard steel, you get some useful weight reductions. That takes a bit longer because it's got to be designed into the vehicles.

So lots of things can happen at different time scales--and then very long-term ideas like plug-in hybrids where we share the energy used for driving with electricity. And, of course, the hydrogen economy is being worked on seriously, but its implementation is still some ways away.

Your report said that biofuels would play a smaller role than anticipated. Why did you find that?
Heywood: Land availability is a constraint. How rapidly can we build (biofuels production) up? Can we distribute these alternative fuels so that we could use them?

When we look at the numbers from a couple of years ago when legislation was written setting some very ambitious targets, we're really not going to beat those targets on that time frame. Now, that's not to say that biofuels won't develop, and I think they will play a useful role overtime--they're one of the few options, real options that we've got. But we've got to be very careful about the environmental impacts and unintended economic impacts of how we go about it.

So do you think this national goal of getting one third of our liquid fuel needs provided by biofuels by mid-century is too high?
Heywood: Well, I'm not going to say no because if you go mid-century that's a long ways away. I think in a nearer-term sense--say going out 25 years instead of 40 to 50 years, 20 percent, maybe 25 percent (from biofuels) that may well develop. Not guaranteed, but I think that looks plausible and maybe it can go beyond that, particularly if you think of this developing in a global sense.

There has been a dispute whether plug-in hybrids are a technology that will scale. Venture capitalist Vinod Khosla says that because they're too expensive, they'll never be used in large numbers outside of rich countries. What's your view on the roles of plug-in hybrids?
Heywood: Well, he's got a valid point. The batteries as we currently see them--even allowing for some development--are going to be expensive. In a plug-in hybrid you need a lot more battery so the incremental cost of that battery, which will depend on the electric range which you want, is going to be significant.

Depending on the cost of fuels that may well pay for itself over the life of the vehicle, but will that be 15 years from now, 20 years from now? We'll be doing that kind of economic calculation much more carefully than we're doing it today at the individual vehicle level.

I think that there is a broad trend of increasing electrification of our energy system, and using electricity and transportation in this way certainly does cut back on petroleum use significantly. So I think it's got a lot of drivers pushing it in the right direction. Now it's going to depend on how quickly can we pull the battery costs down. There's a good shot at making these sensible total economic packages, but it's not guaranteed.

If it's a couple of thousand dollars extra to share the energy between petroleum and electricity, that's likely to be an attractive proposition. If it's $5,000 extra, then that's not as good, and if it's more than that, that's fairly worse.

What policies need to be put in place to promote these new technologies?
Heywood: Our recommendation was that these changes need to be incentivized in some way. Now we've put in some strict CAFE (Corporate Average Fuel Economy) standards that are going to force the industry to move as rapidly as they can and improve the fuel consumption of their vehicles. Those targets are surprisingly aggressive--they're not as easy to realize as the broader public imagines.

I think that there are a number of reasons why over time this country needs a transition to taxing energy consumption in useful ways that motivate people to be more efficient in the technologies that they buy and then how they use these technologies.

If you do tax fuels, it's a revenue source for improving our roadway infrastructure, which is in strong need of reversing the downward slide in terms of its deterioration. And then (that would pay for) even providing some additional aspects to the infrastructure that would improve its capability of having people move with less congestion and save energy that way.

I also think that a fee and rebate system (where consumers get a rebate for buying an efficient car) at the time of purchase motivates vehicle purchasers to pay attention to the fuel economy.

I just happen to have gone through some car buying lately. It's really hard to hang onto your toughness. When you look at all the other things that matter about a car and the other things that we like about cars, it is really hard to hang onto the more stringent stuff that is indeed going to matter. But it gets pushed into the background a bit at time of sale.

Someone would come back and say if you put more taxes on gasoline consumption it's people who are hurting economically who will be further disadvantaged. What's the response to that?
Heywood: One can recycle some of that back to the tax system if one takes an appropriate but thoughtful view of this issue that you've raised.

I'm not saying I know the answer, but I think our strong point is that there are significant opportunities but they need incentivizing. If you want to take the last 25 years, there has been better technology in U.S. vehicles. Performance of vehicles has escalated enormously. Size and weight have gone up significantly and fuel consumption stayed roughly constant. Now, you can say, that's because gasoline was cheap. Fair enough, but if we just rely on "the market," the last 20 years of the market hasn't helped this.

How do you think hydrogen vehicles will evolve? Will they be a niche market?
Heywood: Fuel cells though are very different (from hybrids) and they're going to need a brand-new fuel infrastructure--hydrogen--and it's not easy to put that in. So I don't think they're a niche market. They will get out in some limited fleet testing. But whether it starts to take off in a serious way towards big time depends a lot on whether we see good ways to produce hydrogen that fit our future energy strategies much better. There are lots of questions, people working hard on these questions, but it's going to hover at the modest level for quite awhile before we get a sense of whether this is ready for big time.

You've been advocating for better fuel economy and less polluting vehicles for quite some time. What's your level of optimism right now?
Heywood: Well, I think we are going in the right direction. This period where the prices of oil is high--and I think it may go down some, but it's not going to go down to pretty high levels--that will continue to motivate people to shift what they do.

But it's harder than we think it is to realize on these opportunities and particularly to realize on them in a very broad way, to make the nation's fuel consumption go down. The fleet is growing all the time because the population is growing. So, I think we've got to work very hard to try and incentivize the steps that we have outlined and others have outlined.

This is going to be a hell of a problem to sort out and really make progress on, particularly if you look to what reductions in greenhouse gases people are looking for by mid-century. I mean those are very, very aggressive and ambitious targets (and) they may well be necessary. So there's lots of action in the near-term and the midterm and we really need some good ideas for the long-term.