Eli5 Why did the mid 70’s to late 80’s America produce some of the least aerodynamic looking cars, despite being in the middle of the race to increased efficiency?


As I understand it, the gas crisis of the mid 70’s saw everyone shifting from making/buying cars that were either as big or as powerful as possible and getting sometimes single digit gas mileage to much more fuel efficient vehicles. But while cars got smaller and lighter and engines got handicapped for the sake of efficiency, it seemed that cars of this period were some of the least aerodynamic vehicles since the dawn of automobiles, especially compared to the bubble cars of the 40s and 50s. This seems counter productive.

In: Engineering

Aerodynamics for cars were not well understood until the late 70’s and 80’s and car manufacturers didn’t really think about it that much. Making cars lighter and limiting engines was a lot easier and auto manufacturers mostly didn’t have things like wind tunnels.

So car manufacturers did make aero friendly cars, but they were mostly intended for racing. The average street car was a brick. Earlier cars from the 50’s and 60’s look far more aerodynamic than they actually were. The rounded surfaces often were structural rather than aerodynamic, it wasn’t about moving the air around the car so much as the support it’s weight and shape.

Body panels in this era were all made by hand, but by the 70’s machine made parts and unibody cars started to appear which caused them to take on a squarer shape.

Even in the top echelons of motorsport like Formula 1 they didn’t really understand or use aero until in the mid 70’s.

They knew from aircraft that thin and narrow cars sliced through the air better, but cars built to channel air around them to make downforce didn’t really appear until the mid 70’s.

If you consider that the auto industry is often 10 years behind racing, then car manufacturers didn’t really start thinking about aero until the mid 80’s.

Even the famous Lamborghini Countach looks sleek and aerodynamic but it’s actually a pig. Stick it in the windtunnel and it’s awful. The spoiler does nothing and the car generates lift instead of downforce. So just because a car *looks* aerodynamic doesn’t mean that it is!

Looking back, it’s funny to see how the 80’s in reality was just as blocky as the 80’s computer graphics. It was also the time when computers starting taking over manufacturing designs, and their 8 bit resolution manifested in the items it produced.

Here is a bunch of videos about that period, known as malaise era: https://youtu.be/hnMh5rTe-KY
It’s a deep and fun dive into the question

My 86 Corolla had a very low coefficient of drag but was all angles. You can’t tell by looking if something is aerodynamic or not. Just look at a new Prius. Brought to you by WTF designs.

1935 Tatra T77a was .212

VW beetle was .48

84 Audi 5000s was .36

08 Tesla Roadster was .35

86 Corolla cd was .34

86 Taurus was .32

95 Mazda Mellenia was .29

92 Subaru SVX was .29

21 Prius is .24

So not all that much progress.

Until 1940 to 1958 there was only one legal headlight assembly in America, single 7″ round sealed headlights. In 1959 they allowed dual 7″ round headlights per side (vertical or horizontal were fine).

In 1975 they legalized square headlights that are so iconic of 1980’s vehicles. It wasn’t until 1984 that they legalized unsealed headlight assemblies with replaceable bulbs molded in a variety of shapes that could flow with the rest of the shape of the car.

When you’re only allowed one headlight assembly with a vertical face pasted to the front of the vehicle, it’s going to limit the amount of reasonable looking vehicle designs. Before composite headlight assemblies, the only way to make a reasonably good looking car with sealed beams starts with a flat, vertical nose.