Measuring and Improving Cooling System Performance – Part 3: Diffuser
"Diffuser" is one of those terms that lots of car modifiers use but very few understand. In popular car culture, diffusers are rear bumper garnishes or add-ons that somehow magically create downforce, and you will find lots of these faux diffusers available for purchase at online retailers. You might be surprised to learn that nearly every car manufactured in the last 20 years has at least one actual diffuser on it (most have open rear diffusers now too—"open" because they lack sides and thus are not true diffusers. The ground forms one wall of these diffusers while the opposite wall is a plastic panel under the trunk or, quite often, the muffler). The incorporation of this real diffuser into basic car design has had important effects in improving cooling system capacity and reducing cooling drag in modern cars. It isn't there for downforce, yo ; it isn't just for race cars; and it isn't found at the rear of the car. The most important diffuser in y...