Oil capacity: Let me check. The DF037 engine has an oil capacity around 6.5 to 7 liters. Oil filter needs to be considered for maintenance.
Engine design features: Direct injection or indirect? It's a direct injection engine with a mechanical pump and fuel injection pump. The turbo model would have an intercooler? No, wait, in the DF series engines, the turbo model (T) is equipped with a turbocharger without an intercooler, as intercoolers became more common later in engine developments. So the DF037T has a turbocharger but no intercooler.
Wait, maybe I should look up the actual configuration. DF037 has an aluminum cylinder head with a single camshaft for the two valves per cylinder. The injection pump is driven by the camshaft. Therefore, the DF037 is an SOHC engine.
Restoration and modification tips: For enthusiasts, modifying the DF037 to improve performance might involve upgrading the turbocharger (if T version) or injection pump. However, due to the engine's design and materials, pushing it too hard could lead to reliability issues. Improving cooling and using high-quality lubricants can extend engine life.
First, I should outline the basic specs. Cylinder layout, number of cylinders, displacement. Since it's a four-cylinder, inline configuration. The displacement is 1,586cc or 1,590cc? Some sources might round it to 1.6L. Let me check the exact figure. Yes, the DF037 is a 1.6L engine.