Rare Rides Icons: The Cadillac Eldorado, Distinctly Luxurious (Part XIII)

As we learned in our last installment, the Cadillac lineup was revised visually for 1957, and would be revised again in 1958 once quad headlamps became legal. Fins grew, hoods smoothed, roofs leaned backward, and there were more Eldorado variants than ever before. But styling and lineup changes weren’t the only new features in 1957: Cadillac was also eager to tout its Standard of the World engineering, safety, and engine advancements!

The new Sixty-Two of 1957 was again the basis for the standard Eldorado, with the all-new Eldorado Brougham based on the Series 70 four-door platform. Sixty-Two continued on the C-body as it had in its fourth generation. As mentioned previously, the new 1957 C-body saw a half-inch increase in wheelbase, to 129.5 inches. 

That slight stretch was accompanied by a new chassis design, as the C-body (and all Cadillacs in 1957) adopted a tubular X-frame setup. Notably, the new design lacked side rails. Cadillac claimed this change allowed for a lower body height while maintaining the same space inside the cabin, and provided increased torsional strength.

The height claim was true, as the Eldorado and Sixty-Two saw overall height decrease from 62 inches in 1956 to 59.1 inches in 1957. Remember that for decades a longer, lower, and wider look was the aim of the domestic manufacturers. But the frame design wasn’t the only update for the brand, as there was quite a list.

Other advancements across the lineup included a new front suspension with a spherical joint design. Rear springs were relocated slightly for better handling and stability. The track front and rear was newly uniform, at 61 inches. 

The rear axle of the C-body was upgraded in 1957 with a new, heavier-duty housing and larger bearings. The differential’s gear tooth angle was new, and promised more quiet operation. The braking system received a new power unit, and the emergency brake was activated and released via a pedal on the floor (previously a hand-activated pull bar). Driving refinements continued with a new coupling for the Hydra-Matic four-speed automatic.

All Cadillacs breathed easier via a new dual exhaust in 1957. The company’s engine was thoroughly updated that year, and the edits meant the 365 cubic inch (6.0L) OHV V8 produced 300 horsepower as standard, up from 285 the prior year. Worth mentioning, the old 331 cubic inch (5.4L) V8 from 1956 that dated back to 1949 was discontinued. 

While 300 was the new base horsepower figure, Eldorado Biarritz and Seville offered an upgraded carburetor for 325 horses. Extra power was supposedly exclusive to Biarritz and Seville, though modern sources indicate extra power was available on any model. The 365 V8 also featured larger combustion chambers, a better piston design, and a revised 10:1 compression ratio. 

Other engine changes included a new lower carb with larger secondary barrels, a new air cleaner, and larger intake valves. There was also a new intake manifold, exhaust manifold, a higher output alternator, a larger radiator, starter motor, and finally a new location for the battery so it didn’t get so hot. Though all the engineering changes were baked into every model across the lineup, there were also revisions to the optional equipment list. 

All cars used a revised heating system that was more effective, and there was a new radio design. There was an automatic trunk release button too. And that most luxurious of features, air conditioning, featured a new design on Sixty Special and 62, with a new rear-mounted design on Series 75. Cars were coming to the end of the era where heating was an optional extra.

There were a bevy of new interior details in 1957, with a padded instrument cover, new knobs, courtesy lights, steering wheel, and revised placement of window switches. Front seats in all models also offered a greater level of adjustment. Styling was revised throughout the cabin, with new upholstery materials, door panel design, and instrument panel layout. Even the sun visors were new, as they locked into place and were full-width with the windshield.

But those features didn’t get much attention, as the general public almost immediately reacted to one specific engineering choice again and again: the tubular X-frame. It appeared on Cadillac (as expected) first in 1957, then spread to Chevrolet and Pontiac in 1958. Engineers knew the tube design had better rigidity than a traditional, rectangular ladder frame. 

GM called it the Safety Girder system. The rocker panels, cowl, and body crossmembers were reinforced into an integrated and semi-unitized frame. All parts worked together to reinforce the car structurally and make it safer, with no frame rails needed.

The public focused on that last part, the lack of frame rails. Without them, general consensus was that there was almost no protection in the event of a side impact. There was no crash testing at the time as such, so there was no way to say one way or the other. 

But what did happen were many crashes where people died at the wheel of an X-frame GM car. The company was sued over the safety of the X-frame in 1961, in Evans v. General Motors Corporation. The lawsuit came after the driver of a 1961 Chevy wagon was killed in an accident. GM didn’t win the case, but they didn’t really lose either. 

The court did not rule whether the X-frame was safe, but stated a manufacturer had no legal obligation to make its vehicles either “accident proof or fool-proof.” GM walked away with carte blanche on safety and continued building X-frame cars. Regulation didn’t change until the NHTSA Safety Act of 1966. That legislation set an expectation: Automakers had to exercise a reasonable level of care for passenger safety in their designs. 

Each GM brand went their own way with the X-frame (funny, that brand independence). Cadillac and Chevrolet would use the X-frame through 1964, while Pontiac used it only from 1958 to 1960. Oldsmobile was wisest of the group, as its engineers opted never to produce an X-frame vehicle. Buick opted into X-frame later, and used it on full-size models from 1961 to 1964, and kept it in use on Riviera through 1970.

Other manufacturers of the time stated their traditional perimeter frames were safer, and GM’s foray into the X-frame proved the only domestic example ever to occur. We’ll pick up next time with a review of the Eldorado’s new exterior styling for 1957.

[Images: GM]

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