Brazil's Alcohol-Powered Cars

In the early 1980s, Brazilian automakers were working intensively on the development of alcohol-powered cars.

| November/December 1980

Earlier this year, the Brazilian auto industry began marketing alcohol-powered cars. But, surprisingly enough, fuel from farms isn't new to that nation's motoring scene. In fact, a minimum of 5% alcohol has been blended with the country's pump gasoline — though somewhat erratically, because of variations in the sugar cane harvest — since 1931! And, as a result of the nation's adoption of a "pro-alcohol" program in 1975, as much as 20% of each gallon of auto fuel now sold in Brazil is pure ethanol.

The gasoline blends never affected the motor industry directly, because a standard car needs no engine modification in order to burn such hybrid fuels. But in light of the government's ultimate goal of replacing petrol completely with 185-proof alcohol, Brazilian auto companies suddenly found themselves faced with a major decision: either develop alcohol-powered cars or lose much of their market.

The Solutions

MOTHER EARTH NEWS' editors visited with representatives of General Motors and Volkswagen of Brazil to determine precisely what the industry had done to produce reliable ethanol-burning cars and trucks. Naturally, each factory had its own way of satisfying the technical requirements set by its engineers, but — predictably — the mechanical alterations themselves were virtually identical for every motor manufacturer ... which serves to reaffirm the fact that alcohol fuel technology is now well beyond the "by guess and by gosh" stage.

The automakers directed their attention toward eight areas of modification:

[1] Increasing the compression ratio. Since the "octane" rating of ethanol is well over 100, engine compression can be raised to take advantage of the fuel's antiknock qualities. Although the alcohol/ water blend is capable of withstanding a 15-to-1 ratio, the factory-produced ethanol engines don't exceed 10.5 to 1; costly forged components would be required to do so, and fuel mileage figures don't increase appreciably when compression is raised to the upper end of the possible scale.

[2] Preheating the intake air. In order to help vaporize the alcohol, heated air (up to 210°F) is taken from a jacket surrounding the engine's exhaust manifold and directed into the air filter shroud. This flow is controlled by a vacuum-sensitive valve that provides cooler ambient air — at wide open throttle — to prevent ignition ping and deliver a denser fuel mixture charge under acceleration.

mother earth news fair 2018 schedule


Next: April 28-29, 2018
Asheville, NC

Whether you want to learn how to grow and raise your own food, build your own root cellar, or create a green dream home, come out and learn everything you need to know — and then some!