The Toyota 3S-GE (originally titled 3S-GELU in transversely-mounted applications with Japanese emission controls), is an in-line 4 cylinder engine in the S engine family, manufactured by Toyota and designed in conjunction with Yamaha. While the block is iron, the cylinder head is made of aluminium alloy. The pent-roof combustion chambers are complemented by a cross-flow intake and exhaust layout. The spark plug is located in the center of the combustion chamber. The firing order is 1-3-4-2, with cylinder number 1 adjacent to the timing belt. The 3S-GE was designed to be light, the first iteration 3S-GELU weighing in at a low .