Although luxury cars with more than eight cylinders came and went mostly during the Depression era, some 1960s Cadillac concept cars at least entertained the notion of resurrecting their glamor. And why not? After all, Cadillac's experience with such cars dated from distant 1930, when its V-16 bowed at least a year ahead of every other domestic multi-cylinder engine.

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©2007 Publications International, Ltd. Early work toward postwar V-12 and V-16 Cadillacs produced this scale model, photographed at the GM Technical Center to look like a full-size car. See more concept car pictures.

The cars Cadillac powered have long ranked among the greatest of the Classics, and the V-16 itself was arguably the most important engine to emerge from that era save the hallowed Duesenberg J straight-eight.

What's more, only Cadillac really profited with multi-cylinder power. Before demand tailed off in mid-1930, General Motors' prestige division shipped over 2,000 Sixteens, more than all the 16-cylinder Marmons built in three years.

Lincoln and Packard didn't have anything comparable until 1932, and then "only" V-12s. By that point, Cadillac had a V-12 of its own, and the make's combined multi-cylinder sales were always the industry's highest by far, if modest by absolute standards.

©2007 Publications International, Ltd. Probably fashioned around 1961, this Cadillac concept car wears 1963-type lower-body styling and fins. The long nose would accommodate the long engine.

But multi-cylinder giants were an arrogant indulgence for "hard times," and most were gone well before World War II. The main reasons were high production costs and selling prices versus very low demand, which forced Packard and even Cadillac to abandon such cars entirely after 1940. Though Lincoln's small "cheap" V-12 persisted through 1948, it was obsolete long before.

An added blow to multi-cylinder American cars in the postwar period was the advent of high-octane gasoline, which allowed smaller engines to produce comparable power via overhead valves and higher compression, thus eliminating the need for more than eight cylinders. With that, the ohv V-8 became Detroit's engine of choice. By 1955, every U.S. make offered at least one.

©2007 Publications International, Ltd. This V-12 hardtop coupe concept car was proposed in May 1963. Its rear fender lines would show up in modified form on the 1967 Cadillac Eldorado.

Nevertheless, the expanding prosperity and sky's-the-limit optimism of the Eisenhower years soon renewed thoughts of 12- and 16-cylinder engines, only with modern, high-compression ohv heads.

Go to the next page to learn more about the race for putting a multi-cylinder car on the market during the 1960s.

For more on concept cars and the production models they forecast, check out:

• Concept Cars
• Future Cars
• Consumer Guide auto show reports
• Classic Cars