GM produced a blockbuster Cadillac for 1948 so no one expected much in the way of new excitement from Cadillac for the 1949 model year. They were wrong. Not only did the new engine give the car unequalled performance and ability, but it did so at a substantial gain in fuel economy. The engine weighed in at nearly 200 pounds less than the old L-head, but because it ran cooler, it required less radiator mass, making the savings in weight even greater (220 pounds). Cadillac was able to offer all this, plus an engine which allowed for sleeker styling due to the fact that it was five inches shorter and four inches lower than the L-head. The new powerplant was designed to take full advantage of higher-octane postwar fuels because it could tolerate a compression ratio of 12.0:1 or more. By 1948, 88-octane premium fuels were reaching the pumps, and higher octanes were promised by the oil companies. The engine was a sensation, so much so that it was rushed off to race tracks across the country. Almost-stock Caddys with big racing numbers plastered on their sides were seen roaring down race track straightaways within a few short months after the '49 models were introduced. The cars were so hot folks took the Caddys racing, even to the 24 hours of Le Mans in France. There, a near-stock Coupe de Ville finished tenth overall against the world's finest racing machinery.
Even though the new OHV V8 was the big news for 1949, there were minor trim differences. The 331 cu in (5.4 L) engine produced 160 hp (119 kW). The higher-priced series again had grooved, front fender stone shields and bright rocker panel moldings. Chevrons below the taillights were no longer seen. A heater was optional. Sales in 1949 reached a record 55,643.