A car's intercooler may not be as visible as its snazzy paint job, but it is an essential component for keeping the car cool. Without it, the engine could easily overheat, causing damage, failure, or even a fire. Much like the radiator cools hot engine fluid, the intercooler cools the hot air that the engine emits. This is necessary for a couple of important reasons. First, hot air does not contain much oxygen, which the engine needs to run. Second, it prevents overheating. Because engines come in many different sizes, there are many different types of intercoolers. Universal intercoolers work with different types of engines, which makes them easier to source and install, but choosing something more specialized can help you get more performance out of the part. Small intercoolers work well with lighter engines and do not add a lot of extra bulk or weight under the hood. Large intercoolers have the stamina to cool bigger engines, which means they fit well within large, powerful vehicles. Bigger units also come in handy when the engine has to do a lot of work, hauling for example. Sellers on eBay offer a large inventory of different cooling systems and kits suited for many various vehicles.