A vehicle fluid heat exchanger system comprising: an elongate heat exchanger body that includes: a first fuel port at a first end of the elongate heat exchanger body; a first heat transfer fluid port at the first end of the elongate heat exchanger body; a second fuel port at a second, opposite end of the elongate heat exchanger body; a second heat transfer fluid port at the second end of the elongate heat exchanger body; a fuel flow path between the first and second fuel ports; a heat transfer fluid flow path between the first and second heat transfer fluid ports, the heat transfer fluid flow path being parallel to, and beside, the fuel flow path; a heat transfer wall between the fuel flow path and the heat transfer fluid flow path; a first plurality of fins (212a-c) extending from the heat transfer wall into the fuel flow path; and a second plurality of fins (212d-f) extending from the heat transfer wall into the heat transfer fluid flow path; a first protrusion extending into the fuel flow path opposite the first plurality of fins; and a second protrusion extending into the heat transfer fluid flow path opposite the second plurality of fins. an elongate heat exchanger body that includes: a first fuel port at a first end of the elongate heat exchanger body; a first heat transfer fluid port at the first end of the elongate heat exchanger body; a second fuel port at a second, opposite end of the elongate heat exchanger body; a second heat transfer fluid port at the second end of the elongate heat exchanger body; a fuel flow path between the first and second fuel ports; a heat transfer fluid flow path between the first and second heat transfer fluid ports, the heat transfer fluid flow path being parallel to, and beside, the fuel flow path; a heat transfer wall between the fuel flow path and the heat transfer fluid flow path; a first plurality of fins (212a-c) extending from the heat transfer wall into the fuel flow path; and a second plurality of fins (212d-f) extending from the heat transfer wall into the heat transfer fluid flow path; a first protrusion extending into the fuel flow path opposite the first plurality of fins; and a second protrusion extending into the heat transfer fluid flow path opposite the second plurality of fins. a first fuel port at a first end of the elongate heat exchanger body; a first heat transfer fluid port at the first end of the elongate heat exchanger body; a second fuel port at a second, opposite end of the elongate heat exchanger body; a second heat transfer fluid port at the second end of the elongate heat exchanger body; a fuel flow path between the first and second fuel ports; a heat transfer fluid flow path between the first and second heat transfer fluid ports, the heat transfer fluid flow path being parallel to, and beside, the fuel flow path; a heat transfer wall between the fuel flow path and the heat transfer fluid flow path; a first plurality of fins (212a-c) extending from the heat transfer wall into the fuel flow path; and a second plurality of fins (212d-f) extending from the heat transfer wall into the heat transfer fluid flow path; a first protrusion extending into the fuel flow path opposite the first plurality of fins; and a second protrusion extending into the heat transfer fluid flow path opposite the second plurality of fins.