Computational Fluid Dynamics (CFD) is a wonderful tool, allowing aerodynamicists a way to visualize and optimize airflow in a way impossible in the real world. It can also be used for sillier aims. Like comparing the aerodynamics of a 40-series Toyota Land Cruiser to a loaf of bread.
We've always joked about this sort of thing, but YouTube channel Premier Aerodynamics actually went and did it. And shockingly—or, maybe not—the bread actually wins. The bread's 0.57 drag coefficient isn't great, but it beats the Land Cruiser's 0.66. Additionally, the Land Cruiser generates about 52 pounds of lift at 45 mph, the bread generates virtually none. How you accelerate bread to 45 mph is up to your ingenuity.
The rounded profile of the top of the bread loaf helps airflow stay attached along its length, minimizing the wake at the rear. The flatter bottom of the bread isn't quite so good, so you get some air detaching, but the video host notes that you could improve this by rounding off the sharp corner of this particular loaf. Obviously (?) the bread has a large frontal area, though, so there's a lot of air hitting it, which is why it's somewhat draggy.
The big problem with the Land Cruiser is, well, it's a tall, square truck with big wheels and lots of exposed mechanical components underneath. Its very nature is what makes it so compromised. Of course, the 40-series Land Cruiser was never meant to be some sort of streamliner: It was meant to be a tough off-roader, and that it is. It doesn't matter that its aero is... worse than a loaf of bread. But it is funny.
