Copper/brass V-Cell heater cores were introduced in the 1950s as the first copper and brass design and used until the 1990s. This style has the look of a honeycomb and, in most cases, the top tank of the heater core features a large "V" shape. As time has passed, aftermarket applications have gone to an aluminum design.
Crimp tank heater cores mainly cover import applications from the 1980s to early 2000s. As an older style, this type of heater core is made up of mostly copper and brass.
Expanded tube heater cores, also known as mechanical heater cores, first hit the market in the 1990s for Chrysler and high-end import applications. This style consists of copper tubes, aluminum fins, and plastic tanks. There are some models that do not have a bottom tank, therefore the tubes are exposed. Aftermarket models with this style have been designed with aluminum tubes and O.E. applications have started following suit.
Aluminum heater cores first appeared in the mid-1990s on domestic applications and some import models. Today, it is the most common style in the industry. With aluminum tanks and tubes, the appearance of this type of heater core can vary depending on the applications. Newer models may look like an evaporator with heater tubes and some even have the heater valve already incorporated.