Only one straight-seven engine for land propulsion is known to be in production, the AGCO Sisu 7-cylinder diesel engine. This engine configuration was chosen because of size, parts commonality, and power range issues. A straight-8 would be too long for the farm machinery application the engine was intended for, whilst a V engine would require a higher investment compared to the expected low sales volume for this power range. The straight-7 configuration is a lower investment because Sisu has reused cylinder heads from their I3 and I4 diesel lineups. This is possible because the cylinder volume, pistons and con rods are identical across the Sisu model range.