engineerguy.com
YouTube Twitter Facebook
engineerguy.com YouTube Twitter Facebook
engineerguy.com

home

books

videos

audio

speeches

awards

about bill

PZEV

February 17, 2004

A public radio commentary

Listen carefully, I want to tell you a secret about the auto companies. It's something that they've done almost covertly and it changes the quality of the air you breathe.

At the same time as they've built bigger and bigger environmentally unfriendly SUV's, they've created a car whose exhaust is cleaner than the air outside. Yes, that's right they have a car that produces nearly zero emissions.

I don't mean that they've created a prototype car, or have one in a research lab, but one that you could go out and buy today. Ford, Toyota, Honda, BMW, Mitsubishi, and Volvo all have versions available.

It's called a PZEV, pronounced PEE-ZEV, which stands for Partially Zero Emissions Vehicle. Like most cars today, it's powered by an internal combustion engine, and it has a tailpipe that emits exhaust, but exhaust that contains a tenth of the smog-causing emissions of typical car. In fact, the exhaust is often cleaner than the air in many cities, and amazingly the PZEV cost only a few hundred bucks more than a conventional car.

Now, why hasn't this made headlines? The reason lies in this: There was no key and startling breakthrough. As an auto company vice-president explained: "It's no one thing. It's attention to a lot of details." You see, a PZEV results from using today's technology in careful and purposeful ways.

Here are some of the unexciting details, just to give you an idea. Most pollution causing emissions are released when cars warm up, their catalytic converters - the device that treats the exhaust before it leaves the car and remove pollution - don't work well when cold. So the engineers moved the catalytic converter closer to the engine, heating it up and significantly reducing pollutants.

Next, the car makes use of the computer revolution. As the engine starts it has to be fed a mixture of fuel and air in just the right combination, if not then the fuel doesn't burn completely, letting pollutants escape. A tiny computer monitors the engine and slightly changes the ratio of fuel to air at each stage of starting.

And lastly, here is a major change that helps keep pollution down, it is so unexciting, but highlights so well why the amazing PZEV makes no headlines: They changed the leaky plastic gas tank used on most cars for an air-tight steel one!

So, you can see that a PZEV car isn't flashy. Think of the headline: "Engineer does job competently; makes incremental advance." But do watch out for these incremental advances, in the past they have often changed the world.

Copyright 2004 William S. Hammack Enterprises