You’d think after Streamline Moderne captivated the world in the 1930s and 1940s, automobile design would’ve been nothing but solidified slick, smooth shapes that’d cut through the air with ease from then on. Well, there were quite a few that were, however by the late 1950s you’d think that Cadillac never got the memo, because the iconic 1959 Eldorado was hilariously un-aerodynamic.
I know, the sky is blue and my pen name ought to be Captain Obvious. But really, it’s fascinating how terrible the big beautiful Caddy really was, and YouTube channel Premier Aerodynamics goes into detail about all of the many marks against it in this short-yet-informative video. The company behind this channel specializes in all things aerodynamics instruction; in fact, its website states that “the instructor of these courses has a PhD in aerodynamics, with experience in airplane aerodynamics, automotive aerodynamics, and turbomachinery aerodynamics – experimentally and numerically (CFD).” So, they’re probably well-versed in not only all of the concepts behind figuring out the Eldorado’s effect on displacing air, but also explaining it in a crystal-clear fashion.
Not only is its drag coefficient as large as its wheelbase, but there’s a bunch of similarly sized fare that’s noticeably smoother when it comes to air flow. Let’s get into it.
After running the ’59 Eldorado through a computational fluid dynamics (CFD) simulation, there’s a lot to unpack. First, the wake of displaced air behind it at 45 mph is absolutely massive, especially above the windshield. Then, the front wheels create a wake that’s around double the size of modern cars, and the overall wake ends up being a whole car-length past its fins.
The images are fascinating to look at, too. This isn’t a scene from Akira, it’s the simulation showing exactly where all that air tumbles off to, and how, after it hits this open-top yacht:
Actually, yachts are designed to cut through water reasonably efficiently; this thing batters through nitrogen and oxygen.
All said and done, the Eldorado’s drag coefficient is 0.89. Luckily gasoline was like, half-a-penny per gallon or something back then (it was actually around 30 cents). This figure is brutal; the 2019 Ford Raptor sports a 0.59, and even the 1977 Lincoln Continental Mark V—The Prince of Malaise—had a 0.55. Owl-like compared to the Eldorado.
By comparison, some of today’s slippery-est are half of those: The aptly named Lucid Air’s is 0.197 and the latest Mercedes E Class has a 0.23. As stated in the video, the average car nowadays has a 0.27. Man, how far we’ve come.
What are some of your favorite aerodynamic and un-aerodynamic automobile designs?
How about some analysis with the top up, or comparison with a more modern convertible with a usable second row? The only thing this tells me is a large convertible with the top down has a poor Cd. It tells me almost nothing about the particular shape of that Eldorado.
The vast majority of technically oriented articles on Autopian are fantastic, but this one is lacking in some pretty basic critical thinking.
Well, I may be acquiring some CFD simulation hardware and software in a not so distant futur for my fledging company.
If you guys like simulations, I could get you some nice post processing of whatever shitbox you’re able to provide a CAD file of.
Holy crap if you have a drag coefficient that is 2x a jeep wrangler wow!
I was entertained to discover that pickup trucks deliver better drag numbers with their tailgates up as opposed to down. The raised gate catches a rolling bubble of air that acts like a kammback to the rest of the airstream, robbing a bit of power to nevertheless sharply reduce overall power consumption. With the gate down on the other hand, the entire bluff back end of the cab becomes a big pressure wake, captured by the sides of the bed to make it suck even harder.
I always knew the Eldo and some of its contemporaries were terrible drag-wise, I just didn’t know HOW terrible. .89 is dreadful awful.
Has nobody told you ??
“Earl’s dead, Cadillac for sale,
An Eldorado sits out on the Tamiami Trail.
Sign on the windshield tells the whole tale
Earl’s dead Cadillac for sale.”
This article takes me back to the early days of the interwebs, when this was one of the first of those fancy newfangled “memes” I ever saw:
https://www.wranglerforum.com/attachments/99a48faa-8ad7-444f-8a8f-6fe384e2b195-jpeg.4543603/
Can we get a Toecutter analysis on that cow?
“Low frontal area and smooth edges, the Cd is probably around 0.18. At an estimated weight of 1000 lbs you could probably get a 350 mile range with a 5 kWh battery.
But how could that be it has tail fins? Full marks for including Akira reference.