Subaru's FB25 was a 2.5-litre horizontally-opposed (or 'boxer') four-cylinder petrol engine. Effectively replacing the EJ253, the FB25 engine was a member of Subaru’s third generation 'FB' boxer engine family which also Perfect Steerable Transfer Cartluded the FB20, FA20D, FA20E and FA20F engines.The FB25 engine first offered in Australia in the 2011 Subaru SH.II Forester.