What are you working on?

My interest has been in the energy area. Most recently, I’ve been working on ways to make cars more effi cient while still being stringent on air pollution regulations and also trying to minimize the cost of improving fuel economy. The goal is to make fuel-efficient cars that are economically attractive to people ––that is, cars that people would want to buy because there is an economic benefi t. In this way, my colleagues and I feel that
technology really has an impact. We want to see vehicles such as these in wide use so that there will be a signifi cant overall reduction of oil consumption and green house gas emission.

Leslie Bromberg, John Heywood, and I have been working for some time, in different ways, to make engines more effi cient. Lately, we’ve been working on a concept we call the Ethanol Turbo Boosted Gasoline Engine. The idea here is to use a very small amount of ethanol to enable a very signifi cant increase in fuel effi ciency of a gasoline engine at very low cost. Injecting the ethanol directly into the cylinder enables much higher
performance. It allows you to get a lot more power out of a small, high-efficiency engine and therefore replace a larger engine. Through this replacement, we believe that the fuel efficiency gain will be close to that obtained by a hybrid vehicle, but at a far lower cost.

One of the reasons the gasoline hybrid enjoys a signifi cant increase in efficiency is because it uses a small engine most of the time, and when more power is needed, it uses the electric motor with the stored electricity from the battery. What we’re doing with our highly turbocharged engine is analogous to the hybrid in that we also have a very small engine most of the time, but when we need the high power we use very aggressive
turbocharging, and we actually think it’s a more effective system than storing energy in a battery. Also, in contrast to a hybrid, where the weight of the vehicle is actually increased because of the weight of the battery and all the extra equipment, here the weight of the vehicle would be reduced. This is because we’re taking a big engine, like the V8, and replacing it with a four-cylinder engine, which is much smaller, has a lot of turbocharging, and a high compression ratio. Again, we get a lot more power out of the small size engine
while operating it much more efficiently. So, that’s one of my major interests right now.

[ ... ]
for full text see VISIONS - MIT Interviews book