Before 2005, the domestic made engines show the following characteristics: high concerntration, single kinds, high homogeneity, obvious two polarization.

• 2005年以前，国产发动机市场呈现以下主要特征：产业集中度较高；产品结构单一，同质化倾向明显；柴油发动机市场的"两极分化"形式加剧。