GM Coverup Exposed: 100-MPG Carburetor Exists! We drive Precept, the swoopy car hiding the secret carburetor MILFORD, MI - Chalk one up for the probing journalist, and remember that you read it here first: General Motors Corp. really has been leading a decades-long conspiracy to keep the 100-mile-per-gallon carburetor off the market.

I know, because I just finished driving a GM car that gets 80 mpg (2.9L/100 km) - and it wasn't even running perfectly! Okay, the crafty engineers at GM's proving grounds here are way too smart to let me actually see the carburetor, but after more than a decade of investigative automotive journalism experience, believe me when I tell you it had to be in there.

Gary Witzenberg, a GM spinmeister extraordinaire, handed out a lame cover story about the car, called the Precept (see WAW - Oct. '99, p.86). A real cock-and-bull tale about an industry/government collaboration to build a "new generation" of cars that get incredible mileage. Yeah, right - the car industry and the government - cooperating?

Mr. Witzenberg must think I just fell off the apple cart if he expects me to believe any car company in its right mind would share the secrets of the 100-mpg carburetor. Yet GM's cover story is so immaculate, it even concocted a plausible acronym for this phantom "cooperative program:" PNGV (Partnership for a New Generation of Vehicles).

The engineers also did their best to throw me off the track, screening the magic carb with technical jargon about "hybrid" power (get this: an electric motor driving the front axle and a 3-cyl. turbodiesel powering the rear wheels, as well as something called an "MPU.") Moreover, they honestly expected me to believe the car - which clearly is constructed of nothing more than a bunch of aluminum cans pounded into a batmobile shape - is the world's most aerodynamic 5-passenger sedan. They claim its coefficient of drag is 0.163, which is way better than a lot of airplanes!

Anyway, as soon as I drove this thing, it was obvious it all comes down to the 100-mpg carburetor. I mean, when you pull away, it doesn't even make any sound. Their cover story, of course, provided an explanation. Something about the using the electric motor to start off, then "effortlessly" starting the diesel engine with the MPU.

There's a lot of talk about that diesel engine, too: they insist it's in the rear end, but you can't hear it, and any fool knows it's impossible to silence a diesel.

The brakes feel a little weird, too, and they mumbled about "regenerative braking" at both axles. These GM screwballs really ran with that tale, insisting that when slowing down or using the brakes, the electric motor and the MPU turn into generators to feed power back into the "hybrid" system.

This so-called MPU, hooked onto the end of the diesel, must have been designed by Star Trek's Scotty: it also throws in 10 kiloWatts of power during wide-open-throttle acceleration, helps to damp vibration from the engine and provides power for the air conditioning and heat while the car's stationary. That's important because - and get this - the engineers say everything shuts off to save energy when the car's standing still. I am not making this up; the GM guys regurgitated all of this with straight faces.

I'm saving the best for last, though. There's a little bit of jerkiness when accelerating (which, you can be certain, is the carburetor switching to ultra-stealth mode) and one particularly convincing GM engineer regaled me for 10 minutes with a tale of an "automated manual" transmission, fabricated from bits of an Opel unit. Man, these guys must put in mega-overtime to think up this stuff!

After that, I'd had about enough of this folly, because it was obvious this "Precept" is just a shell to hide the carburetor.

For example, the seats were so lightweight they practically weren't there (of course the engineers claim the seats were deliberately constructed that way) and the thing didn't even have any mirrors. Yeah, you guessed it: The story is that they hooked up cameras to provide a panoramic rear view - that way they could eliminate the drag-inducing outside mirrors.

It gets better. There are no bulbs in the car - all the lighting except the high-intensity discharge (HID) headlights, they say, is light-emitting diode (in fact, this is one of those kernel-of-truth details car companies use to inject credibility: GM's current Cadillac DeVille actually uses LEDs for its taillamps). And you've gotta give 'em credit for this whopper: "zero-drag" disc brakes on the front axle that help to reduce rolling resistance. This too, is a technology claimed to be in the wings for "regular" (i.e. non-100-mpg-carburetor) production vehicles.

Now you know why auto journalists who lug around titles like "senior technical editor" draw down the large coin: It's guys like me who keep the huge companies like GM from bamboozling suckers like you. Through my sources, I've known for some time about the secret carburetor, so I easily saw through GM's elaborate "PNGV" red herring.

What's more, I made 'em think I believe it all. I didn't even snicker when the engineers said this car would be ready for a road-going demonstration program in just four years.

So take it from an expert: the 100-mpg carburetor exists. I've driven it.