Air entering the charge cooler will meet a heat exchanger with cool liquid flowing through it. Pressure loss (or flow restriction, whichever way you want to think about it) across this heat exchanger is minimal, only on the order of 0.25 psi. Some air-to-air intercooled systems can lose 3 or more psi before reaching the engine, often thanks to the extra plumbing needed to get compressed air to a front-mounted air-to-air intercooler. In addition, the "open" fin nature of Vortech's air-to-liquid heat exchanger causes less pressure loss per unit area compared to the more restrictive interior of an air-to-air heat exchanger. This is one of the reasons air-to-air intercoolers are often larger in size: to compensate for this effect and reduce their pressure loss.