Abstract: A heat exchanger for a motor vehicle exhaust includes a tubular body having a first end, a second end, a peripheral sidewall, and at least two flow passages that extend between the first end and the second end. The at least two flow passages include at least one heat exchange fluid flow passage and at least one bypass fluid flow passage. A heat exchange coil is positioned in the at least one heat exchange fluid flow passage. The heat exchange coil has an inlet and an outlet extending through the sidewall of the tubular body. A valve is provided for selecting between the at least one heat exchange fluid flow passage and the at least one bypass fluid flow passage.

Abstract: A heat exchanger for a motor vehicle exhaust includes an outer tubular body and an inner tubular body. The outer tubular body has peripheral sidewalls, an interior cavity, a first end and a second end. The inner tubular body has fluid impervious sidewalls formed out of a single length of conduit wound in a spiral coil. The spiral coil has an exterior surface and an interior surface. The inner tubular body is disposed within the interior cavity of the outer tubular body spaced from the peripheral sidewalls. This provides a first flow channel between the exterior surface of the inner tubular body and the peripheral sidewalls of the outer tubular body, and a second flow channel along the interior surface of the inner tubular body. The conduit of the spiral coil has an inlet end and an outlet end, whereby fluid is circulated through the coil.

Abstract: A heat exchanger of a hydrocarbon fuelled motor vehicle includes a tubular body having a first end, a second end, and fluid impervious sidewalls formed out of a single length of conduit wound in a spiral coil. Connections are provided at each of the first end and the second end of the tubular body for coupling the tubular body with an exhaust pipe.